procedure in sealing and unsealing mine …/67531/metadc40317/m...in mine fires; and spontaneous...
TRANSCRIPT
UNITED STATES DEPARTMENT OF THE INTERIORhAROLD L. ICKES, Secretary
BUREAU OF MINESJOHN W. FINCH, Director
Miners' Circular 36
PROCEDURE IN SEALING AND UNSEALING MINE
FIRES AND IN RECOVERY OPERATIONS
FOLLOWING MINE EXPLOSIONS
REVISED MARCH 1938
By
J. J. FORBES and G. W. GROVE
UNITED STATES
GOVERNMENT PRINTING ÓRFICE
WASHINGTON 1938
After this publication has served your purposeandif;ou have no further need for ¡t,please return it to the Bureau of Mines, using the official mailing label on the last page
For sale by the Superintendent of Documents, Washington, D. C. - - - - Price 15 cento
IntroductionAcknowledgmentsCauses of mine fires and expio-
5i0115Hazards of mine fires and explo-
sionsImportance of rescue and re-
covery operationsOrganization
Preliminary organizationOrganization chartsTraining officials and ap-
paratus crewsTemporary organization
Examining fanCutting off electric power
from mineWarning and directing un-
derground employees - - - -Placing guardsCalling assistanceRoping off mine areaWarning connecting and ad-
joining minesPreparing to enter mine - -Checking in and out
Permanent organizationMan in charge of operations_Underground organization
Man in charge of shift - -Oxygen breathing-appara-
tus and gas-mask crewsBrattice crewsTrack crewsMaterial crewsMiscellaneous crews and
personnelSurface organization
General headquarters. - - -Lamp house and atten-
da.ntsMessroom and attendants.Sleeping quarters and rest
roomsApparatus room and at-
tendantsInformation bureauEmergency hospitalMorgue and attendants - -Laboratory and atten-
dantsMiscellaneous crews and
personnelEquipment
Oxygen breathing apparatusand gas masks
OONTE NT S
It
PageEquipmentContinued.
Devices for detecting gases - - 15Devices for illumination 15
Permissible electric lamps.. - 15Cap lamps 15
Edison 15Wheat 16
Flash lamps 17Eveready fiashlight. - -. 17Megolite flashlight 18Tuffite flashlight 19
Miscellaneous lamps 19Fire-fighting devices 19
Fire extinguishers 19Hand extinguishers 19
Carbon tetrachloride 19Soda-acid 20Foam 20Carbon dioxide 21
Mounted extinguishers 21Chemical 21Water 21
Hose, nozzles, and connec-tions 23
Rock dust 23Tools 24Telephones 24Maps 25Locomotives, animals, and
cars 26Analytical apparatus 26Pumps 26Clothing 26Miscellaneous equipment 26
Materials 27Brattice cloth 27Lumber 27Nails and spikes 27Brick, concrete blocks, and
tile 27Portland cement 27Wood fiber 27Posts and timbers 28Pipe and pipe fittings 28Wire, insulators, hangers, etc 28Miscellaneous materials 28
Procedure following mine fires. 28Methods of control and ex-
tinguishmentof mine fires 29Fighting mine fires by direct
attack 29Use of water 30Use of chemicals 30Use of rock dust 30Use of sand 31
Pagei
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666
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Procedure following mine fires-Continued.
Methods of control, etc.Con.Sealing mine fires
Temporary stoppings orseals
Brattice clothWood
Permanent stoppings orseals
PrickCement blocksConcreteTileWood and plasterPack wall
Flooding mine firesFlushing mine fires.Use of incombustible barriers
to prevent spread of fireLTse of inert gas
Unsealing mine firesFactors governing time for
unsealingExtent and intensity of
fire at time of sealing -Characteristics of burning
material and overlyingstrata
Tightness of seals and en-closed area
Influence of barometricpressure and tempera-ture on enclosed area
Effect of ventilation onsealed area
Sampling and analysis ofatmosphere under seal_
Composition of fire gasesin sealed area
Typical examples of mine-fire gases
Horning mineOakmont mine
Conclusions regardingtime to unseal fires_ - -
Preparations for unsealing_Ventilation and rock dust-
ingFan and fan attendant_Electric power cut-out - -
Methods of unsealing minefires
Recovering sealed regionby use of air locks - - - -
Procedure used in unseal-ing Horning mine_ - -
CONTENTS
PageProcedure following mine fires-
Continued.Tlnsealing mine firesContd.
Methods of, etc.Contd.Procedure used, etc.Con.
Construction of seals. 58Analysis of atmosphere
behind seals 3 hoursafter sealing 58
Construction of stop-pings and air 1ocks 58
Analysis of atmospherebehind seals 4 daysafter sealing 58
Details of reopeningsealed area and re-covery of bodies 59
Final unsealing of Horn-ing fire area 60
Outstanding factors insuccessful unsealingof Horning fire area 61
Recovering a sealed areaby reventilation 61
Recovery procedure followingmine explosions 62
Examination of mine openings 62Establishing ventilation 62Entering mine and establishing
fresh-air base 63Establishing telephone com-
munication 64Duties of rescue and recovery
crews 64Explorations ahead of fresh air. 64Restoring ventilation 66
Construction of stoppings_ - 66Control of ventilation 67
Examining for and extinguish-ing fires 68
Rescue and removal of live meit 70Handling bodies 71Setting timbers 72Clearing roadways 72Preparation for resuming oper-
ations 72Rescue and recovery operations
course 72Procedure before going under-
ground 75Surface arrangements 75
Procedure after going under-ground 75
First exploration 76Advancing fresh air 76
Recommended rules of proce-dure 77
Page
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ILLIJ S TRATTO NS
Pig. Page
Organization chart for coal-mine fires or explosions 5Organization chart for metal-mine fires 5Edison (model K) electric cap lamp 16Super-Wheat (WTA) electric cap lamp 17Permissible Eveready (metal case) flashlight 18Eveready (industrial model) flashlight 18Megolite flashlight 18Chemical fire truck 22Water fire truck 23Portable (batteryless-type) telephone 25Brattice-cloth stopping 33Brick stopping 35Brick and tile stopping recommended by the National Mine Rescue
Association 36Concrete stopping 37Erecting a tile stopping -- 38Board stopping plastered with wood fiber 39Stopping of patent lath plastered with wood fiber 40Sketch of plank and tarred-felt stopping 41Sketch of pack-wall stoppings 43Sealed fire area in the Oakmont mine 48Sketch of procedure of recovery work, Horning mine 57Officials in charge of shift checking over crews and equipment before
going underground after an actual explosion 63Oxygen breathing-apparatus crew starting an exploration trip with
reserve crews at the fresh-air base 65Gas-mask crew erecting a brattice -cloth stopping 67Section of the Everettville mine in which air locks were used 69Class in rescue and recovery operations receiving instruction in use of
equipment 73Problem in rescue and recovery work after explosions 74
V
PROCEDURE IN SEALING AND UNSEALING MINE FIRES AND INRECOVERY OPERATIONS FOLLOWING MINE EXPLOSIONS'
By J. J. FORRES 2 and G. W. GRovE
INTRODUCTION
This publication is a revision of the last of the series of fourminers' circulars to be used in a course of training that will preparemine officials to organize men for rescue and recovery work. Thefirst of this series (Miners' Circular 33) discusses mine gases andmethods of detecting them; the second (Miners' Circular 34) givesinstruction in Bureau of Mines methods of sampling mine gases anduse of the portable Orsat apparatus for analyzing air samples; thethird (Miners' Circular 35) describes the methods and equipmentused in protection against mine gases; and the fourth (the presentpublication) explains the procedure in sealing and unsealing minefires and in recovery operations at time of or after fires or after ex-plosions. This circular discusses organization, equipment and ma-terials, and procedure in fighting, sealing, and unsealing mine fires,and in recovery operations following explosions; a practice problemfor recovery procedure also is included. Although the data contamed in this publication relate primarily to comparatively thin ormedium thick coal beds with little if any pitch, it is believed that theprocedure for sealing and unsealing mine fires, together with theprinciples and technique of identifying fire gases, is applicable, withmodifications in some cases, to metal mines and coal beds, whetherthick or thin and with varying pitches. This circular is a revisionof Miners' Circular 36 issued originally in 1929,
ACKNOWLEDGMENTS
Acknowledgment for assistance in the preparation of this cir-cular is made to D. Harrington, G. S. McCaa, C. W. Owirigs, E. J.Gleim, A. B. Hooker, and M. W. von Bernewitz, all of the Bureauof Mines. Acknowledgment is made to the Hillman Coal & CokeCo., Pittsburgh, Pa., and the Pittsburgh Terminal Coal Corpora-tion, Pittsburgh, Pa., for permission to use maps and data relatingto the Oakmont mine fire and the Horning mine fire and explosion.
i Work on this manuscript completed January 1929; printed in 1929, revIsed and re-printed in 1938.
2 Supervising engineer, Safety Division, Bureau of Mines.8 Mining engineer, Safety Division, Bureau f Mines,
1
2 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
CAUSES OF MINE PIRES AND EXPLOSIONS
The basic cause of mine fires and explosions (except those due tospontaneous combustion and friction) is an igniting agent in con-tact with combustible material, explosive gas, or coal dust.
Combustible material, such as coal, timber, wooden doors, stop-pings mine cars, explosives, brattice cloth, and other combustiblesubstances, together with explosive gas or coal dust or both, arepresent in most coal mines, some of them in virtually all undergroundnoncoal mines as well; therefore, unless proper precautions are taken,a fire or an explosion is possible in almost any mine, and certainlyno coal mine can be considered immune from fires or explosions.
The igniting agents of mine fires are electric arcs and sparks;open lights, matches, explosives (especially if blasting is done withblack powder) ; ignitions of gas or coal dust, which, in turn, resultin mine fires; and spontaneous combustion and friction.
The sources of ignition of mine explosions are electric arcs andsparks, open flames such as open lights, mìne fires, matches, andblown-out shots (particularly if black blasting powder is used), andexplosions of unconfined or improperly confined explosives.
Regardless of the type, it is necessary for the igniting agent to bein contact with combustible material to cause a mine fire, or withan explosive mixture of gas or a cloud of coal dust to result in anexplosion. Therefore, a gas explosion is possible only if an explo-sive mixture of gas is permitted to accumulate and be ignited, andcoal dust cannot explode unless enough is allowed to collect so thatit can be ignited and propagate or extend flame and violence.
In recent years, probably 90 percent or more of the mine firesand 75 to 80 percent or more of the explosions have been iiitedby electriciÈy. Consequently, reat care should be exercised in in-stalling, operating, and maintaining electric wiring, machinery, andequipment, particularly at and around the face region in coal mines,because gas or dust or both are likely to be found there at any time.
In considering matters connected with those affairs, the principalobjective of the careful, conscientious mine official should be to pre-vent mine fires and explosions by eliminating, so far as possible,sources of ignition and by preventing the accumulation of explosivegas and coal dust.
HAZARDS OF MINE PIRES AN]) EXPLOSIONS
Mine fires and explosions are an ever-present hazard; in fact, theyare the greatest hazard that confronts officials and men in the opera-tion of mines. They not only jeopardize the life of every man work-ing in the mine but the lives of the men who participate in rescueand recovery work. In addition to the cost in human lives, thedollars-and-cents cost of mine fires and explosions is so great thatthey constitute a heavy tax on the organizations affected by themand one that is readily avoidable.
The most common hazards in connection with mine fires are theasphyxiation of men by smoke and fumes, often in distant parts ofthe mine as well as in proximity to the fire; injury or death of menby falls of roof while fighting, sealing, or unsealing the fire; or
HAZARDS OF MINE FIRES AND EXPLOSIONS g
ignition of an explosive mixture of gas or coal dust that may injureor kill underground workers. To those who must work on them,mine fires are far more hazardous than are explosions, as the explo-sion has usually done its harm while the mine fire may at any timecause an explosion or other untoward occurrence with possible deathto those in the mine engaged in handling the fire.
Undoubtedly a mine fire in a dry, dusty bituminous-coal mine thatis liberating explosive gas in or in the vicinity of the fire area isthe most hazardous to combat and extinguish. There is not onlythe danger of a gas explosion but the greater hazard that even asmall gas explosion may ignite coal dust, or a fall of roof may throwa cloud of coal dust into the air which may come in contact with theflame of the fire and produce a widespread and destructive explosion.
Fighting a fire in a gassy anthracite mine, involving several coalbeds, also is extremely hazardous because of the danger of a gasexplosion; there is also the possibility that highly heated poisonousgases may be encountered, unexpectedly by those in the mine whomay not be equipped to resist their harmfulness.
Fire in a metal mine generally is not as hazardous to combat asfire in a coal mine, because explosive gas is rarely found in metalmines and explosive dust is rarely a factor; however, the smoke,fumes, and gases given off by metal-mine fires usually are hard tohandle because ventilation in many metal mines is inadequate andpoorly controlled. Many metal mines depend largely or entirely onnatural ventilation, which is stopped or even reversed when a fireoccurs; and in any event, the lack of control of air flow in so-callednaturally ventilated mines (coal or metal) is hazardous in theextreme when a fire occurs. If adequate mechanical ventilation,properly controlled, were maintained in metal mines, the hazardsfrom fighting a fire would be substantially lessened.
The usual hazards of mine explosions are that men may be burnedor otherwise injured or killed by the heat and violence of the explo-sion; that men may be affected, overcome, or killed by the gasesresulting from the explosion; and that another explosion may occur,due to fires or smoldering embers, and injure or kill additional men.Undoubtedly mine explosions are most dangerous when bituminousor lignitic coal dust is involved. A coal-dust explosion, or ignitionof explosive gas that later results in a dust explosion, may spreadthroughout the entire mine and even to the outside of the mineExplosion of a cloud of fine bituminous or lignitic coal dust canoccur without the presence of explosive gas, but a coal-dust explosion,ignited directly or by a gas explosion, will not propagate or spreadif the mine is adequately and properly rock-dusted. However, if adust explosion occurs and a mine is not rock-dusted or is onlypartly rock-dusted, the explosion may travel or propagate throughmost or all of the mine An explosion involving explosive gas onlyalso is extremely dangerous. However, the force of a gas explosionwill be "local" or limited to an area required for the heated gasesto expand; and, unless a fairly large body of gas accumulates, acomparatively small portion of a mine usually is affected.
It should be emphasized that without an efficient organization, suit-able and adequate equipment and materials, and proper procedure,the hazards of mine fires and explosions will be increased greatly.
61985°-38-----2
4 Paul, J. W., and WollEn, H. M., Rescue and Recovery Work in Mines After Fires andExplosions: Handbook, Bureau of Mines, 191G, 101 pp.
4 PROCEDURE IN SEALING AND NSEALING MINE FIRES
IMPORTANCE OP RESCUE AND RECOVERY OPERATIONS
The necessity of prompt and correct procedure to save live menwho may be entombed, the safety of those engaged in the work, andthe prevention, as far as possible, of additional property damagemake rescue and recovery operations after mine fires and explosionsextremely important.
Immediately following the occurrence of a mine fire or explosion,and probably for some time thereafter, there is likely to be excitement,confusion, and disorganization among the officials and workmen.Frequently little or nothing of importance is done, or wrong actionis taken, with resulting needless loss of life of entombed men or ofthose engaged in rescue and recovery work. Naturally, when minemanagement and workmen are confronted with conditions that usuallyare entirely foreign to their experience, wrong methods are likely tobe used.
Most mine officials have never had a disaster in their mine andtheir ordinary operating experience is of little value in controllingthe abrupt changes that take place in and around a mine after a fireor explosion. Moreover, the official in charge may be greatly dis-turbed by the loss of subordinate officials, friends, and possibly rela-tives, and the general loss of life and property, so that his otherwisesound judgment and reasoning powers may be affected seriously.
The most important things for speedily, safely, and efficiently con-ducting rescue and recovery operations after mine fires and explosionsare: (1) Efficient organization, (2) adequate and proper equipment,(3) sufficient materials, and (4) proper procedure in performing thework. All of these are highly essential and will be discussed in con-siderable detail.
The authors of this circular have had rather wide experience inassisting with and directing rescue and recovery operations follow-ing mine fires and explosions, and have included information on themost important or essential things to be done and how to do them.
ORGANIZATION
The necessity for a capable and efficient organization to carry onrescue and recovery operations after a mine fire or an explosion cannotbe overemphasized.
The personnel comprising the organization should be of the highesttype obtainable, well trained, and preferably with considerable ex-perience in the duties they are to perform. To know what to do andhow to do it and to apply such knowledge promptly often may savethe lives of entombed men and prevent needless risk and possibly lossof life by men engaged in rescue and recovery work.
The numerous explosions and fires tlìat have occurred in well-equipped and well-operated mines indicate clearly that much thoughtand consideration should be given at all mines to preparation for suchemergencies.4 Lack of efficient organization after mine disasters fre-quently has resulted in loss of life and property and in unnecessarilyprolonged recovery operations.
IN CASE OF COAL-MINE FIRE OR EXPLOSIONNotify Chief State Mine Inspector and District Mine Inspector
Chief Inspector Address
District Inspector Address
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GENERAL ORGANIZATION AND PROCEDURE$uPEiUNTENDET'Ti
Information Bì.au.Furnhsh Information to press and others.Guard.,Ropc off and guard all mine entrances. Regulate traffic on
rcad, l.sdia to usIne.Mine Cb'rk.Stpy by telephone, preferably where the superintendent
has sitablished headquarter..Have two min for errand duty.
Oulside )'oreman.Provlde iqformetlon bureau, messrooms, emergencyheap *i,54Ìkis, rest roonsi, aMaleeping quarters.
supply Clerk.Stsy at your post. Provide the following for immediateuse: Nails heattice cloth, hatchets, axes, saws, picks, boards, props,shovels, identif cation checks, electric cap lamps, flame safety lampe,telephone., *ltes, and insulators, atretchera, and flr-gjd eabhwta,
Aisq provide for persons authorized by manainçati Overalls, gumshoes gum boots gloves cape electriç asfety benpa and flashlights
4cçqrd all equipment issuç4 .i4 rctutne4,
Nl ie=zPt4l tn4 leah i ediatsiy, when sutliqeisad by niperin.al! alertala switehes whcea alcardeity enters the mine,
Peaviila material namiad to caray any additional telephone eqasmunica.
Fan 4ttendant,s-fltay at fan and sar that it is running, Rave machinistpr sPielen mehr any necessary repairs,
tntrti ehou.flend awn, or go yourself, to assist machinlutgl aP4cjan WIth fan or other necessary wprk,-ppeiot ¡lippaien to atay in shop..
heck au4 .ansp Men.- ipqed in lamp house with adjoining room.)flpr 1tt egc man receyng lamp has been approved by the supina.
tendent45ecord all equipment issued and returned,Give each man a check number; record his nun*cr and name In a book.
MIN!MVM EQUIPMENT FOP' MINE BESCUII STATIONS
SUPERINTENDENTContinued,Final Cheek Men.(Stationed within the roped-off area at each
entrence.)
Allow no persona to enter the mine except those authorized by theofficials in charge.
Examine each man carefully for smoking articles and matches. Makeno exceptions.
- Check each man in and out by number and name; note time in a hook.Note that each snan is fully equipped for the work he is to do.
MINE FOREMAN.Have fan inspected. Do not reverse ventilation exceptafter consultation with all responsible officials present and afterissuing written order.
Organize underground operations in cooperation with superintendentand with State inspector, when he arrives.
CHIEF ENGINIIER.Take to headquarters copies of maps showing regularcoursing of air, location of regulators, overcasts, stoppin0, doors,and pumps, substations, motors, and other machinery; also obtainsnaps of adjoining mines.
OTHER SUPERINTENDENTS AND FOREMEN.Assemble your organ-ization as per chart for immediate call. Stay by telephones of yourrespective plants until told to leave by general superintendent.
DIRECTOR OF SAFETY AND INSPECTION.Assemble apparatus men;assemble first-aid men. Orgviize crews for their respective shifts.
Arrange for: Rescue and recovery operations; emergency hospital;ambulance crvìce; physicians; and Red Cross work.
i thousand-foot life line on a reel.I Pesai app&fttus and means of taking sir samples:1 anemometer and i psychrometer.
esnary binde and I CO detector.Brattlee lqth, board., nail., copper hammer., sad
i misse t.lsphone and wire.1 mree-aun fire extinguishers and fire hose.1 oxygen Inhaler.i first-aid ehiaet complete.1 woolen blanket,.1 set of splints complite.1 ¿trmy stretcher.I list of apparatus men with telephone numbers,
IsouxaL'Organisation ehert fer cosi-usina finas or 4,hssìoe..O19$5'-'4$ (l'ace p. ) No, i
Telephone - -- - -
Telephone
BUREAU OF MINES SAFETY CARSANt) STATIONS
The Bureau of Mines operates li mine safety carsand 11 mine safety stations.
In case of disaster, notify ti. S. Bureau of Mines,at Experiment Station, 4800 Forbes Street, Pitts-
- burgh, Pa., or at one of the following places:Juneau, Alaska. Norton, Va.San Francisco, Calif. Phoenix, Ariz.Birmingham, Ala. Salt Lake City. Utah.Denver, Colo. Seattle, Wash.Duluth, Mino. Vincennee, bd.Jellico, Tenn. Wilkes-Baste, Pa.McAlester, 0km. Dallas. Vex.
NOTIFY
QNEM )4OEROIfERAL SUBERINTENDENT
MINE SUPERINTENDENT
Chief Eugineer. Mine Foreman.DIRECTQR
Safe Pcpnttssint
AT ONCE IN Electrical Engineer. Aasistant Mine Foreman.- -
fChief, State Papeatment Fire Bosses.THE 01111ER Assistant, Outside Foreman.
Platelet Mine inspector. Other apparatus men. Electricians.NAMEI
W, fi, Bureau of Minee (Pitia. Other Sat.d wen. - Machinists.
Other Superiatendeuta. Physidans.
Ambulance service.
Apparatus men.Check and lamp men.
Other offiils,Hospital, Mine Clerk.
pargios s°eq of other divi.sIgns, Red Cross officials. Fire Department.
Bureau of Mhie. Miners' Circular 36 (Revised)
VN1TED STATES DEPARTMENT 0E THE INTERIOR BUREAU OF MINESHarold L. Ickes, Secretary John W. Finch, Director
SURFACE ORGANIZATION AND PROCEDUREFOR METAL-MINE FIRES
Remove Underground Workers Immediately
Notify State Department of Mines and District Mine Inspector
State Department of Mines -. Address Telephone
District Inspector Address Telephone
SUPERINTENDEIiT:Information Bureau.Furnisi inforsnatipn to press and ..nthes.Cuarda.Rope off and guard all mine entrances. Regulate traffic on
roads leading to mine.Mine Clerk.Stay by telephone, preferably where the superintendent
has established headquarters.Have two men for errand duty.
Outside Foreman.Provide information bureau, messrooms, emergencyhospital, provisions, rest room, and sleeping quartera.
Supply Clerk.Stay at your post. Provide the following for immediateuse: Nails, brattice cloth, hatchets, hammers, axes, saws, picks,boards, timbers ahovels, lagging, identification checks, flashlightsand batteries, telephones, wires and insulators, stretchers and first-aid cabinets, overalls, gum shoes, gum boots, gloves, caps, fire hose,nozzles, etc.
Eleetrieian.Look after all electrical equipment and supplies. See thattelephones are in good working order, and provide for additionaltelephones if needed.
Master Mcchanic.Keep attendants constantly at fan, compressors,and hoists.
Mauhiniat.Assist master mechanic. Appoint shopmen to stay in shops.Checkman.(Stationed in supply house.) Make record of all equip-
ment issued and returned. Give each man a check number; recordhis number anti naine in a book.
MINIMUM EQUIPMENT FOR MINE RESCUE STATIONS
10 self-contained oxygen breathing apparatus.1 extra bottle and reducing valve.Extra mouthpieces, breathing bags, and 100
charges of regenerating material.i low-pressure gage.i oxygen pump with spare parts.5 oxygen cylinders (100 Cu. ft. Capacity).I tool box with wrenches and other tools.6 approved flame safety lamps and repair parts.12 approved flashlights or electric cap lamps.6 self-rescuers.5 approved All Service gas masks.10 extra canisters.i list of apparatus men with telephone numbers.
ORGANIZATION AND PROCEDURESUPERINTENDENTContinued.
FiaI(h,kmesi.(Stgtioned within the roped-off area at each en-trance.) Allow no persons to enter the mine except those authorizedby the officials in charge.
Check each man in and out by number and name; note time in a book.Note that each man is fully equipped for the work he is to do.
MINE FOREMAN OR CAPTAIN.Have fan inspected. Do not reversefan except after consultation with all responsible officials present,and only after issuing written order. Organize underground opera-tions in cooperation with superintendent and with State inspectorwhen they arrive.
CHIEF ENGINEER Take to headquarters copies of maps showing regularcoursing of air, location of fans, regulators, overcasts, stoppings,doors, pumps, compressors, substations, motors, underground hoists,and other machinery. Also obtain maps of adjoining mines.
OTHER SUPERINTENDENTS AND FOREMEN.Assemble your organ-ization as pec chart for immediate calL Stay by telephones of yourrespective plants until told to leave by general superintendent.
DIRECTOR OF SAFETY AND INSPECTION.Assemble apparatus men;assemble first-aid men. Arrange for: Rescue and recovery opera-tions; emergêncy hospital; ambulance service; physicians; and RedCross work.
1 thousand-foot life line on reel.1 Orsat apparatus and means of taking air samples.1 anemometer and 1 psychrometer.2 canary birds and I CO detector.Brattice cloth, boards, nails, copper hammers, and
1 mine telephone and wire.5 three-gallon fire extinguishers and fire hose.i oxygen inhaler.1 first-aid cabinet complete.12 woolen blankets.i set of splints complete.Stokes Navy or Homestake stretchers.Fire-fighting equipment.
Fwuaa 2.Organization chart for metal-mine fires.ß1985-.dS (Face p. 5) NO. 2
BUREAU OF MINES SAFETY CARSAND STATIONS
The Bureau of Mines operates 11 mine safetycars and 11 mine safety stations.
In case of disaster, notify U. S. Bureau of Mines,at Experiment Station, 4800 Forbes Street, Pitts-burgh, Pa., or at one of the following places:
Juneau, Alaska. Norton, Va.San Francisco, Calif. Phoenix, Ariz.Birmingham, Ala. Salt Lake City, Utah.Denver, Colo. Seattle, Wash.Duluth, Minn. Vincennes, md.Jellico, Tena. Wilkes-Barre, Pa.McAlester, OkIa. Dallas, 'l'ex.
NOTIFY
GENERAL MANAGERGENERAL SUPERINTENDENT MINE SUPERINTENDENT
Mine Foreman or Captain.DIRECTOR
Safety DepartmentAT ONCE IN Mui.tant Mine Foreman.
TIlE ORDER Chief Engineer.Assistant. Outside Foreman.
Electrical Engineer.Other Apparatus Men. Electricians.
NAMED State Department of Mines.Other First-Aid Men. Machinists.
District Mine Inspector.U. S. Bureau of Mines (Pitts- Physicians. Apparatus Men.
burgh). Ambulance Service. Checkmen.
Other Superintendents. Hospital. Mine Clerk.
Other Officials. Red Cross Officials. Fis-e Department.
Bureau of Mha Miuws' Circular 36 (RevIsed)
UNITED STATES DEPARTMENT 0F THE INTERIOR BUREAU 0F MINESHarold L. Ickea, Secretary John W. Finch, Lireetor
ORGANIZATION 5
Organization for training persomiel and for handling mine dis-asters may be classed as follows: (1) Preliminary, (2) temporary,and (3) permanent. By preliminary organization is meant the selec-tion and training of officials and oxyge.n breathing-apparatus crewsand the assignment of duties and procedure to be followed by localmine personnel in the event of a disaster; by temporary organizationis meant the organization of officials, oxygen breathing-apparatuscrews, and workmen connected with the mine at which the disasteroccurs, with possibly some assistance from nearby mines, which im-mediately following a disaster carries out essential duties until thearrival of additional assistance; and by permanent organization ismeant the organization of officials, xygen breathing-apparatus crews,and employees from the local mine and from other mines and com-panies, State mine inspectors, employees of the Federal Bureau ofMines, and others to function until the recovery work is completed.
PRELIMINARY ORGANIZATION
Every mine should have an emergency organization of officials,oxygen breathing-apparatus crews, and other selected employees whoare trained to take charge and immediately start recovery operationsafter a disaster. The need for preparing for emergencies such asfires and explosions is evident to those experienced in rescue and re-covery work, as they often find at a mine after a disaster a highlydisorganized personnel, total absence of necessary equipment and ma-tenais, and little or no effective effort being made to recover entombedmen or to effect quick and properly safeguarded entry into the mine.
ORGANIZATION CHARTS
An up-to-date organization chart containing the names, addresses,and telephone numbers of State mine inspectors, local mine officials,and members of oxygen breathing-apparatus crews, officials of othermines and companies, the Federal Bureau of Mines, doctors, andothers likely to be of aid is of much value following a mine disaster.The organization chart should contain also a list and the location ofequipment and material required to start rescue and recovery opera-tions. Copies of the organization chart should be posted. in suitableplaces around the mine
Figures 1 and 2 are plans of organization charts for coal and metalmines. Mining companies may use these charts to advantage (pos-sibly with some modificatioiìs to fit local conditions) in training anorganization for disaster work and in obtaining and maintaining es-sential equipment and materials. Copies may be obtained from theBureau of Mines for posting at mines, in offices, etc. Where thesecharts are not applicable, they may serve as a guide for interestedmining companies in preparing similar charts of their own.
Unnecessary loss of life of entombed men and of those engaged inrecovery operations in many instances has been caused by lack ofpreparation and organization or improper procedure. Therefore,before a fire or explosion has occurred considerable thought andattention should be devoted to perfecting an organization to functionsatisfactorily if a disaster should take place.
PROCEDURE IN SEALING AND UNSEALING MINE FIRES
TRAINING OÏFICIALS AND APPARATUS CREWS
Local mine officials, including surface officials, from time to timeshould receive instruction and training in the duties they are toperform individually and collectively should a mine fire or explosionoccur in their mi.ne. They should be informed where tools, bratticecloth, and other equipment and materials may be obtained quickly atthe mine and from adjoining mines, jobbers, mills, hardware stores,etc. All officials should be instructed that in the absence of superiorauthority they are to attend promptly to the most important thingsand notify immediately, according to a list that should be kept avail-able, all persons required to assist at a disaster, particularly the Statemine inspector having charge of the district in which the mine islocated, oxygen breathing-apparatus crews, doctors, the Federal Bu-reau of Mines, and others.
Members of oxygen breathing-apparatus crews should be selectedcarefully and should receive thorough training and instruction in theuse and care of oxygen breathing apparatus and rescue and recoveryprocedure. They should be physically sound and fit to performstrenuous labor under oxygen and should have good judgment and acool, calm disposition.
Additional training and instruction should be given frequently tothe oxygen breathing-apparatus crews in an irrespirable atmosphereto insure that men and equipment are in condition for an emergency,and underground maneuvers, involving a recovery problem, shouldbe conducted occasionally
TEMPORARY ORGANIZATION
Until experienced help arrives and a permanent organizationcan be effected, a temporary organization composed of the local mineofficials and employees should be formed.
In the event that most or all of the local underground officialshave either been killed or imprisoned in the mine or for some otherreason are not available immediately, the senior official outside, orsome employee previously designated, should assume charge andform a temporary organization. The person who is in charge shouldconfer promptly with all those present having mining experience,outline a plan of procedure, and perform other important duties,among which are the following:
EXAMINING FAN
After a mine fire or explosion, the mine fan should be examinedand should be kept running (if in operation) and a man should beplaced in charge to see that it is kept in operation. If the fan hasbeen damaged or destroyed by an explosion, necessary repairs shouldbe made immediately or another fan should be provided. The ven-tilating current should not be reversed without good reason and thenonly after due consideration and consultation; written orders shouldbe issued by the person or persons responsible for reversing the venti-lating current, and generally this duty should fall on a responsibleofficial of the State or of the mining company.
ORGANIZATION 7
CUTI'ING OFF ELECTRIC POWER FROM MINE
Electric power should be "cut off" immediately from the mine andremain off until it is definitely determined that having power in themine will not create a hazard.
WARNING AND DIRECTING UNDERGROUND EMPLOYEES
In case of fire in a mine or mine entrance and after an explosion,an effort should be made to warn those within the mine. Telephonesconnected with the inside of the mine should be used for this pur-pose if they have ñot been put out of commission by the explosion orfire. A mine-fire alarm can be given to different parts of the minemore quickly by telephone than by any other means, except possiblyby the stench alarm system for metal mines or ot.her mines having awider-spread compressed-air system. The telephone system, if onehas been in use, may not be destroyed in all parts of the mine byan explosion; every effort, therefore, should be made to establishtelephone communication with men in the mine to obtain, if possible,information regarding the disaster and to warn and instruct the menthat can be reached. Outside telephone connections should be usedto summon assistance and to order needed equipment and materials.A man should be stationed at all times at an outside telephone thatalso communicates with the inside of the mine.
PLACING GUARDS
Immediately after a mine fire or an explosion, guards should beplaced at all mine entrances to permit no one to enter until ordershave been given to explore the mine and to obtain a record of anymen who come out of it.
Guards, preferably with police powers, also should be placed atroads and paths leading to the mine to protect and control relativesand friends and spectators who rush to the mine and to prevent inter-ference with work. All persons not engaged in the performance ofuseful work should be kept as far as possible from the mine entrancesas a precaution against injury or death by an explosion and in orderto prevent interference with the rescue and recovery work.
Additional guards, or officers, should be assigned to keep the roadsleading to the mine and the available space around the mine open.This is important so persons who have been called to assist in recov-ery work can reach the mine, and so that equipment, material, andsupplies can be delivered.
State police organizations or highway patrols, or both, can be usedto advantage in guarding entrances to mines and keeping roads clear;usually the services of these men can be obtained readily.
CALLING ASSISTANCE
All local employees not within the mine should be called to reportat once, and, when the situation warrants, assistance should be askedof adjoining or adjacent mines and mules at distant points. Thecharacter of the assistance required should be indicated clearly.Oxygen breathing-apparatus crews and experienced mining men with
S PROCEDURE IN SEALING AND UNSEALING MIÑE FIRES
training and experience in rescue and recovery work will be of mostvalue. Other persons who should be notified are: State mine in-spectors (particularly the inspector in whose district the mine is situ-ated), the county coroner, members of local and adjacent mine rescuecrews, surgeons, and doctors in the vicinity of the mine, and theFederal Bureau of Mines.
A list of persons and organizations, with addresses and telephonenumbers, should be kept posted near telephones so they may be noti-fied without delay. A man should be in attendance at all times atthe telephone used for outside communication.
ROPING OFF MINE AREA
As soon as possible after a. mine fire or explosion, substantial ropesshould be placed at some distance from the mine entrance for thesafety of the crowds that collect; to exclude from the mine or itsentrances relatives and friends of those who may be entombed andmay be tempted to take unwtrranted risks in trying to reach theirmen; and to prevent the curious from iñterfering with personsrequired to carry on necessary work.
After the area has been roped off, guards, or preferably officers ofthe law, should keep the space inside the ropes clear. Suitable tagsor other marks, which should be kept visible at all times, should beprovided for all workmen and others who have permission to enterthe roped-off area. Only persons with the proper tag or mark inevidence should be permitted to remain inside the roped-off area.
WARNING CONNECTING AND ADJOINING MINES
Officials of mines known to be connected with or adjoining a minein which a fire or explosion has occurred should be notified promptly,so that men working in the connecting mine may be removed.
Failure to warn promptly or to remove or prevent men from enter-ing a mine connected with one in which a fire or explosion has oc-curred may cause such men to be affected or killed by poisonous orasphyxiating gases from the mine suffering such explosion.
Officials of adjoining mines, whose active or abandoned workingsare in proximity to a mine in which a fire or explosion has occurred,should be notified also that they may take the necessary precautionsto safeguard their underground employees.
PREPARING TO ENTER MINE
After the above and probably other important matters have re-ceived attention from the person in charge, or have been delegatedto responsible, reliable, and competent persons, preparations shouldbe made to enter the mine and start recovery operations. When ex-perienced underground employees, fully equipped oxygen breathing-apparatus and gas-mask crews, gas-detecting devices, and other neces-sary equipment and materials are assembled and ready, recovery workshould be started. Detailed information on conducting recovery workis given iii the sectiQns dealing with procedure following mine firesand explosions,
ORGANIZATION 9
CHECKING IN AND OUT
Arrangements should be made to obtain the check numbers ornames, or both, of any men who come out of a mine after a fire or anexplosion. When recovery work is started, a reliable man or menshould be designated to check men in and out of the mine, to searchmen going underground for matches, lighters, and smokers' articles,and to prevent any but permissible electric cap lamps and flashlightsand properly assembled permissible flame safety lamps in good con-dition from being taken into the mine.
Each man who enters the mine should be given a numbered check.A record should be made of checks and names, with the date andhour of entrance and return to the surface. A check cabin or roomshould be established near the entrance of the mine but not in adirect line with the entry, and a man or men should be stationedthere at all times to check men in and out of the mine
PERMANENT ORGANIZATION
After the arrival of assistance, such as State mine inspectors,Bureau of Mines representatives, mine officials, oxygen breathing-apparatus crews, workmen from other mines and companies, andothers, a permanent organization should be formed. The permanentorganization should take over and carry on the work started by thetemporary organization, perform any other necessary functions thatmight have been overlooked by the temporary organization, and com-plete the recovery work in the safest and speediest possible manner.
The kind of disaster (fire or explosion) and its extent (area in-volved, number of men entombed, killed, and injured) naturally willgovern the size of the permanent organization and other necessaryarrangements. In addition to the requirements indicated for a tem-porary organization, other important functions and arrangements areessential for a permanent organization. When a fairly large disasterhas occurred, resulting in a number of fatalities that will require froma few to several days or more to complete the recovery work, thefollowing and probably other arrangements for a permanent organi-zation should be completed.
MAN IN CHARGE OF OPERATIONS
The permanent organization should be headed by a cool, competentmining man well versed and experienced in the technique of rescueand recovery work, preferably some person who has no relatives orvery dear friends involved in the disaster. The man in charge shouldhave complete authority, and while off duty or away from the minehe should delegate his authority to a selected person, so that someonewho will be recognized as in charge will be available at all times. Inaddition to the man in charge of operations, there sl1ould be as-sembled an advisory committee of mining men thoroughly experiencedin recovery operations, more or less conversant with local conditions,and also well versed in procedure and in the use and limitations ofprotective and detective apparatus and devices necessary for thesafety of those engaged in the recovery operations.
'o PROCEDURE IN SEALING AND UNSEALING MINE FIRES
A plan for the safe conduct of the work should be formulated bythe man in charge and his advisory committee as soon as they haveconsidered the situation and formed their conclusions. There shouldbe no essential deviation from the plan as outlined unless such changeis approved after careful consideration by those in charge.
The man in charge and his advisers should select from the person-nel available the men who are to comprise the various undergroundshifts and the surface organization and should decide on the lengthof shifts.
If the recovery operations are extensive, involving a large mineor a large area, or progress will be slow due to extensive falls orother difficulties, so that days or even weeks may be required tocomplete recovery operations, the work should be arranged in suit-able shifts
Recovery work is hazardous, strenuous, and nerve-racking, there-fore, the shifts should not exceed 8 hours at the most; in fact, bestresults often can be obtained by 6-hour or, in some cases, 4-hourshifts. Due consideration should be given to the type of work re-quired, heìght of coal, degree of pitch, extent of destruction in-cluding fallen rock, and personnel available before deciding on thelength of shifts.
UNDEROROUND OI«iANIZATION
The personnel comprising the underground organization is of theutmost importance as the progress of the work, as well as the safetyof all concerned, will depend on their knowledge and efficiency.
MAN IN CHARGE OF S1III
A man experienced in mine rescue ancj recovery work should bein charge of each underground shift as assistant to the man incharge of the entire recovery operations. He should be well versedin mining work and especially in ventilation, mine gases, detectiveand protective equipment, and procedure following fires or explo-sions. One or more competent assistants and such other personnelas may be necessary to conduct recovery work safely and efficientlyshould be assigned to the man in charge of the shift. If explora-tory and other work is being done by oxygen breathing-apparatuscrews, the man in ciLarge of the shift or one of his assistants shouldalways be at the fresh-air base.
The man in charge of the shift should be provided with an up-to-date mine map on which should be marked as the work progresses,the areas explored, stoppings erected, ventilation restored, locationof bodies, locomotives, cars, pumps, mining machines, falls, andother important data.
Change of underground shifts should be made at the fresh-airbase to prevent interruption of the work. The man in charge of theshift being relieved should discuss with the man in charge of theoncoming shift the progress made and plans for future work. Aftercompleting his shift and reaching the surface, the man in charge ofa shift should report at the general headquarters to the man incharge of operations and convey to the latter the data noted on themine map used on the shift and any other information of importance.
ORGANIZATION 11
OXYGEN BREATHING-APPARATUS AND GAS-MASK CREWS
Well-trained crews, physically sound and fit and experienced inthe use and care of oxygen breathing apparatus and gas masks, arean essential part of any organization engaged in rescue and recoveryoperations. At least some, and preferably all, of the men composingsuch crews should have had experience in actual recovery work.They should be provided with all the equipment, in excellent con-dition, necessary to conduct the work successfully. When explora-tions are being made or other work is carried on with oxygen breath-ing apparatus ahead of fresh air, at least two complete crews withadequately charged apparatus should be available. No oxygenbreathing-apparatus or gas-mask crew should make an explorationor work in advance of fresh air without a reserve crew at the fresh-air base equipped with oxygen breathing apparatus in good conditionand adequately charged.
BRATTICE CREWS
Brattice men, in charge of a foreman, should be provided to erecttemporary stoppings and line brattices of canvas or other suitablematerial where necessary. Temporary stoppings should be rein-forced as soon as possible by stoppings of more substantial construc-tion, such as boards covered with canvas or plastered with woodfiber, or tile, brick, or concrete. As the work advances, men shouldbe assigned to patrol and keep tight the temporary stoppings thathave been erected.
TRACK CREWS
Track men, in charge of a foreman, should repair and clean track.to facilitate the movement of material to the advance workers andto remove bodies (if any) as they are recovered.
MATERIAL CREWS
Material crews, in charge of a fdreman, should be provided to han-dle and transport promptly and efficiently material such as bratticecloth, boards, timbers, nails, food, coffee, water, and other materialfrom the mine portal or shaft bottom to the advance crews.
MISCELLANEOUS CREWS AND PERSONNEL
Miscellaneous underground crews, as timbermen, laborers to cleanup falls, electricians to install and extend telephones, stretcher bearers(if required), and others if necessary should be provided in chargeof foremen. Certified fire. bosses, haulage men, telephone attendants,and all others necessary should be at hand to perform the worksafely, rapidly, and efficiently. All of the foremen in charge of thedifferent crews, as well as the various members of crews and otherunderground personnel, should be under the direct.ion of the manin charge of the shift. and his assistants, who, in turn, should beunder the direction of the man in charge of operations.
No person other than those directly engaged in the recovery opera-tions should be permitted underground.
6198°-38--.--3
12 PROCEDURE IN SEALINO AND UNSEALING MINE FIRES
SURFACE ORGANIZATION
The surface organization should include the personnel necessaryto handle the equipment and materials required iiì recovery workunderground, to provide facilities for housing and feeding the under-ground and surface organizations, and to perform various othernecessary duties.
GENERAL HEADQUARTERS
A room or building near the mine entrance should be designatedand used as headquarters for the man in charge of operations andhis assistants. It should lìave tables, chairs, and telephones connectedwith those being used underground and on the surface around themine. Telephone attendants should be on duty at all times andtwo or more men should be available at general headquarters forerrand duty and messenger service where the telephone service isnot at hand.
An up-to-date mine map should be provided and all importantdata placed thereon to indicate the progress of recovery operations.The men in charge of different shifts, foremen of crews, etc., shouldreport progress to the general headquarters at the end of each shiftSO that officiais, inspectors, etc., may be informed of what has beenaccomplished.
LALP HOUSE AND ATrENDANTS
A suitable building or room should be provided for charging,issuing, receiving, and repairing electric cap lamps and flame safetylamps. Enough lampThouse attendants should be on duty at alltimes to distribute lamps promptly to men entering the mine, to col-lect from those leaving the mine, and properly clean, charge, andrepair the lamps being used; this lamp service is important and itshould be done well.
MESSROOM AND ATTENDANTS
Members of the underground and surface organizations, relativesand friends of persons killed or injured, officials from other com-panies, and other visitors must be fed. For this purpose there shouldbe a commissary and niess in charge of some designated person, withenough cooks, waiters, dish washers, etc., available. The mess shouldbe housed in a suitable building, room, or tent and be provided withtables, benches, stoves, cooking utensils, dishes, etc., so that the per-sons assigned to this duty can have a supply of hot, wholesome foodavailable at all times for those engaged in the recovery work. Hotcoffee and food, particularly fruit, also should be provided and de-livereci to those on duty underground, special effort being made tosupply such food directly to the advance crews.
SLEEPING QUARTERS AN» REST ROOMS
Men engaged in recovery work should have a comfortable place torest and sleep where they will not be disturbed either by the otherworkers or in any manner, as the work is strenuous and demandsexpenditure of both physical and nervous energy. Therefore, if
ORGANIZATTON 13
possible, separate sleeping quarters should be provided for the menof each shift in order that they may obtain the maximum amount ofrest while off duty. Sleeping quarters should be in a quiet place,properly heated in cold weather and provided with comfortable cotsand sufficient bedding
A comfortable rest room, separate and some distance from thesleeping quarters and provided with tables, benches, or chairs, lights,etc., should be available for men not sleeping or not on duty.
APPARATUS ROOM AND AvrENDANTS
A room should be available in which to store, charge, and repairoxygen breathing apparatus, gas masks, and accessories. Thereshould be on each shift at least two men competent to clean, recharge,test, and repair oxygen breathing apparatus and gas masks worn bythe underground crews. To expedite extensive recovery work, it maybe advisable to establish an underground base for cleaning, charging,testing, and repairing breathing apparatus and gas masks. The basemay be moved from time to time to keep it in proximity to workingcrews.
INFORMATION BUREAU
Relatives and friends of persons injured, killed, or missing in amine disaster naturally are vitally concerned in the recovery work.The public is also interested in the property damage, loss of life, andprogress of recovery operations, particularly the rescuing of livemen or recovery of bodies. An information bureau to issue informa-tion to friends and relatives of entombed men and to press andpublic should be established. It should be directed preferably by alocal mine or other company official or State inspector, and authenticinformation should be issued from time to time. Properly handled,an information bureau relieves anxiety and grief of relatives andfriends, prevents injurious comment by outsiders, and obviates criti-cism and misleading statements by the press. All information shouldbe issued by an authorized mine official or a representative of theState department of mines
EMERGENCY HOSPITAL
A fully equipped emergency hospital, with doctors and nurses inattendance, should be established in a suitable building. Men foundllive in the mine may be affected by noxious gases, severely burned,or otherwise injured; or some of those engaged in recovery workmay require immediate hospital attention for injuries ör effects ofirrespirable gases.
MORGUE AND ATTENDANTS
Provision must be made for receiving the bodies of those killed in amiñe disaster and preparing them for burial. If the mine is adjacentto a town or city, it may be convenient or desirable to take the bodiesimmediately to an undertaking establishment; however, where this isnot possible or desirable, an improvised morgue should be established.This building preferably should be located some distance from the
14 PROC}]DTJIIE IN SEALING AND UNSEALING MINE FIRES
mine, should be well ventilated, and should have good drainage facili-ties. A reliable man, with the necessary assistants, should be placedin charge of the morgue to make a record to identify as far as pos-sible all bodies delivered to the morgue and to take possession of per-sonal effects found with each body and deliver them to relatives.Undertakers and their assistants should prepare bodies for identifica-tion by relatives and friends and later for burial.
LABORATORY AND ATTENDANTS
Analyses of mine-air samples are often necessary in planning rescueand recovery operations after a mine fire or an explosion. It may bevitally important to obtain information quickly on the compositionof mine air in a section of a mine, a return airway, or from behindfire seals. A room with suitable apparatus and materials should beprovided with competent attendants available to analyze promptlyand efficiently air samples delivered to the laboratory.
MISCELLANEOUS CREWS AND PERSONNEL
Miscellaneous surface crews, responsible to foremen, should beappointed to obtain, handle, and transport material required under-ground to the mine opening or to the bottom of the shaft, to passout and check equipment and supplies, and to perform other neces-sary duties.
The permanent surface organization should take over and supple-ment, if necessary, the activities and duties performed by the tem-porary organization. Such organization should include a man tobe stationed continuously at the fan; a man or men to search mengoing underground for smoking material, matches, and lighters, totest all flame safety lamps being taken underground, and to checkunderground workers into and out of the mine, and prevent unau-thorized persons from going into the mine; and guards to see thatropes erected to exclude spectators from proximity to the mine en-trance are in place, to keep unauthorized persons outside the ropes,and to see that roads leading to the mine are kept open for trans-portation of men and material.
All of the officials, foremen in charge of crews, and other surfaceworkers, as well as the underground workers, should be under thedirection of the man in charge of operations.
EQUIPMENT
The safety and protection of men engaged in rescue and recoveryoperations demand that an ample supply of the proper type of pro-tective, detective, lighting, and fire-fighting equipment and analyticalapparatus in first-class condition be available.
OXYGEN BREATHING APPARATUS AND GAS MASKS
Self-contained oxygen breathing apparatus and gas masks will berequired by crews working in advance of fresh air, and enough ofthem in good condition, together with spare parts and supplies,should be available. The safe use of approved gas masks will be
5 Bureau of Mines, Permissible Electric cap Lamps, Procedure in Testing, Fees Charged,and Requirements for Approval: Schedule OC, Dee. 21, 1985 7 pp.
iQTJIPM1NT 15
limited to places where a lighted flame safety lamp (or a candle inmetal mines) will burn.
DEVICES POR DETECTING GASES
Safety and good mining practice require that ample means beprovided for the detection of mine gases by competent persons desig-nated to use them. The necessary devices for detecting mine gasesare permissible flame safety lamps, U. C. C., M. S. A.,, or Burrellmethane indicators, possibly continuous methane recorders (mainreturn only), carbon monoxide detectors or canaries or both, andportable gas-analysis outfits. Sufficient supplies and spare parts toinsure efficient operation of the gas-detecting devices should be avail-able at all times. These devices should be used only by personsfully acquainted with them and their limitations.
DEVICES FOR ILLUMINATION
Men engaged in rescue and recovery operations in coal minesshould be provided with permissible electric cap lamps or flashlights,or both, for illumination. In some instances permissible floodlightscan be used to advantage and, if required, should be provided.
In metal mines approved illuminating equipment is also preferable,as it will add to the safety and efficiency of the crews. In moderncoal mines (and many metal mines) approved electric cap lamps areused exclusively for illumination and therefore will be available foruse after a mine fire or explosion. Where permissible electric caplamps are not regular mine equipment, at least 50, with necessaryequipment for charging and repairing, should be provided at theearliest possible moment for use in recovery operations.
PERMISSIBLE ELECTRIC LAMPS
Under Schedules 6, GA, OB, and 6C,5 the Bureau of Mines has ap-proved various types of electric cap lamps, hand lamps, flood lamps,trip lamps, and animal lamps as permissible for use in gassy anddusty mines.
cAl' LAMPS
Various models and designs of the Hirsch, Hubbell, General Elec-tric, Manlite, Wico, Concordia (Ceag), Edison, and Wheat electriccap lamps have been approved. Many of these are no longer manu-factured or usíd and therefore will not be considered. The twotypes of lamps in general use are the Edison and Wheat, several dif-ferent models of which are available. Following is a brief descrip-tion, with illustrations, of the latest models of the Edison and Wheatelectric cap lamps:
Edison (model K) lamp.The latest model Edison electric caplamp (fig. 3) has a three-cell, Edison, nickel-alkali electrolyte batteryin a monel-metal case with a magnetic lock. A bakelite headpieceprovided with a two-filament (main and emergeiicy) bulb, a reflector,
16 PRÖ(EDTTRE TN SEALING AND UNSEALTNG MIN 1TRF
lens, switch for operating the lamp, and a device for fastening to aminer's cap is connected to the battery by means of a rubber-coveredcable. The headpiece switch is designed so that the current can beswitched from either the main or emergency filament or turned on oroff of either filament. The headpiece safety device consists of aspring that holds the bulb in the electric circuit as long as the bulb isintact, but provides that it fal]s out of the circuit if the bulb is
FIGURE 3.Edison (model K) electric cap lanìp.
broken. Tlìe headpiece is also sealed with a lead seal. The Edisonmodel K cap lamp was approved by the Bureau of Mines (approval25) on August 31, 1931. Three bulbs, designated by the symbols B. M.25, B. M. 25A, and B. M. 25B on the base of the bulb, are approvedfor use with this lamp. The complete lamp weighs 5 pounds 6 ounces.
Super-Wheat (model TV. T. A.) lamp.--The latest model Wheatelectric cap lamp (fig. 4) has a two-cell, lead-acid battery enclosed ina molded rubber case. A molded rubber headpiece equipped with a
FIGURE 4.Super-Wheat (WTA) electric cap lamp.
bulbs, designated by the symbols B. M. 20b, B. M. 20e, and B. M. 20don the base of the bulb, are approved for use with this lamp. Thecomplete lamp weighs 4 pounds 8 ounces.
FLASH LAMPS
The demand for approved flashlights for use in rescue and recoverywork and by mine officials resulted in the development of such lamps.Under Schedule 11 and liB,6 the Bureau of Mines has approved thefollowing lamps:
Eveready flas/dight.The first type of this flashlight (fig. 5) con-sists of three dry-cell batteries, polished reflector, bulb, and lens en-closed in a metal case. The case is provided with a switch for operat-
6 Bureau of Mines, Permissible Electric Flashlights, Procedure in Testing, Fees Charged,and Requirements for Approval: Schedule liA, Jan. 13, 1936.
EQUIPMENT 17
two-filament main bulb, a small emergency bulb, a reflector, lens,switch for operating the lamp, and a device for fastening to a miner'scap is connected to the battery by means of a rubber-covered cable.The headpiece switch is designed so that the current can be switchedfrom either the main or emergency bulb and turned on or off eitherbulb. The headpiece safety device consists of springs that hold thebulbs in the electric circuit as long as the bulbs are intact, but pro-vides that they fall out of the circuit if broken. The headpiece is alsosealed with a lead seal. A unique feature of this lamp is that the bat-tery can be charged through the headpiece without disconnecting itfrom the battery. The Wheat W. T. A. cap lamp was approved bythe Bureau of Mines (approval 20) on November 19, 1934. Three
18 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
ing the lamp, and the light can be focused by adjusting the positionof the reflector and the threaded bottom part of the case. There isspace, also, for an extra bulb in the bottom part of the case. Thesafety feature consists of a spring that holds the base of the bulb
FIGURE 5.Permissible Eveready (metal case) flashlight.
in contact with the electric circuit; if the bulb is broken the springejects the base of the bulb and breaks contact. The lamp was ap-proved by the Bureau of Mines (approval 601) on October 22, 1924.
FIGURE 6.Eveready (industrial model) flashlight.
A later type (fig. 6) of the Eveready flashlight (industrial model)has a bakelite instead of a metal case. It also differs slightly in otherrespects, particularly in the focusing, which is accomplished by mov-
FIGURE 7.Megolite flashlight.
ing the reflector only. This lamp was approved by the Bureau ofMines (approval 605) on February 24, 1937.
Megolite flw/tlight.This type flashlight (fig. 7) consists of threedry-cell batteries, polished reflector, bulb, and lens enclosed in acohardite case. It is possible to focus the spotlight by adjusting the
Bureau of Mines, Miscellaneous Portable and Semlportable Electric Mine Lamps, Pro-cedure in Testiftg, Fees Charged, and Requirements for Approval: Schedule lOB, J 1,1932, 6 pp.
61985°-38 4
1QUIPMENT 19
threaded bottom part of the case. An interesting feature of thelamp is that it has no switch; the light is turned on and off by holdingthe lamp and flicking or jerking the reflector end of the lamp.
The safety feature of the lamp consists of a spring that holds thebulb in contact, but if the bulb breaks the base is thrown away fromcontact. The lamp was approved by the Bureau of Mines (approval604) on March 13, 1936.
Tuffite fla/ilight.This type of flashlight consists of either twoor three dry-cell batteries, polished reflector, bulb, and lens enclosedin a tuffite case. The case is gastight, watertight, acid-resisting,and a nonconductor of electricity. The lamp has no switch, the bulbbeing turned on or off by turning the base of the lamp It is alsofocused in the same manner. As a safety feature, the usual springcontact bulb is provided. The lamp was approved by the Bureau ofMines (approval 606) on September 18, 1937.
MISCELLANEOUS LAMPS
Various typs and models of miscellaneous electric lamp have beendeveloped and approved by the Bureau of Mines under Schedules 10and lOB.7 These lamps are designed to meet special requirements orconditions and are as follows: Hand lamps, signal lamps, trip lamps,inspection lamps, animal lamps, and floodlights. Miscellaneouslamps that can be used to advantage in recovery work should be pro-vided as needed.
FIRE-PIGHTING DEVICES
Fire-fighting devices and equipment should be available at allmines, as many mine fires reach serious stages only because properfire-fighting devices such as fire extinguishers, water, hose, and noz-zles, are not available. It is well known that essentially all largefires start as small ones and that usually they can be extinguishedeasily in the early stages if suitable material or equipment is readilyavailable for prompt use.
FIRE EXTINGUISHERS
Fire extinguishers are f two distinct types: Hand extinguishers,which are readily portable and range in capacity from 1 quart toi or 2 gallons, and mounted extinguishers fitted with wheels whichare transported on the mine track and have a capacity of about 4Cigallons to as much as 100 or more gallons. All types of extinguishersshould be tested and inspected regularly and maintained in goodoperating condition.
HAND EXTINOUISHEBS
Various models of small portable fire extinguishers can be obtained.The following types are commonly used in or around mines.
Carbon tetrachloride.T his type extinguisher consists of a seamlessshell, a double-acting pump either enclosed in the shell or attachedto the side of the shell, a handle connected to the pump, a filler cap,
20 PROCEDURE IN SEALINQ AND UNSEALING MINE FIRES
and a discharge nozzle. The chemical charge consists of carbontetrachloride (Cd4). To charge the extinguisher, it is filled withcarbon tetracliloride free of moisture and impurities and treated soit will not freeze until about 50° F. below zero is reached. Carbontetrachloride is an extremely volatile liquid that, in contact with heat,develops a heavy incombustible vapor. The extinguisher is oper-ated by unlocking the pump handle, pointing the nozzle in the direc-tion of the fire, and operating the pump. The pumping action de-velops enough pressure to throw the liquid a considerable distance.This type extinguisher is especially desirable for fires of electricalequipment, as the liquid is a nonconductor of electricity. Carbontetrachloride extinguishers should not be used without respiratoryprotection in confined places or where ventilation is poor, as thevapors and fumes formed by the liquid in contact with burningmaterial are extremely dangerous.
ßoda acid.This type of extinguisher consists of a tank, a wheelcap, a discharge hose and nozzle, an 8-ounce acid bottle, an acid-bot-tle cage attached to the wheel cap, and a loose-fitting lead stopperthat rests in the neck of the acid bottle.
The chemical charge consists of 4 ounces of concentrated sulphuricacid and 11/2 pounds of bicarbonate of soda. To charge the ex-tinguisher, the outer tank is filled with bicarbonate of soda dissolvedin water; the acid bottle, with the lead stopper inserted, is thenplaced in its supporting cage, the cage and wheel cap are placed inthe tank, and the wheel cap is screwed tightly in place.
To operate the extinguisher the operator inverts it, permittingthe loose lead stopper to fall free and the acid and soda solution tomix, and at the same time points the hose and nozzle toward thefire. The chemical reaction in the extinguisher develops a pressureof about 100 pounds, which forces the liquid out of the nozzle. Therange of the stream is about 30 feet, which makes it possible for theoperator to attack the fire from a safe distance.
Foam.This type of extinguisher consists of an outer tank, awheel cap, a discharge hose and nozzle, an inner cylinder extendingthe length of the tank, and a loose-fitting stopper that serves as acover for the inner cylinder. The chemical charge consists of acanister of powdered chemical "A" (aluminum sulphate), a canisterof powdered chemical "B" (sodium bicarbonate), and a can of foam-ing ingredient.
To charge the extinguisher, the chemical "B" is dissolved in luke-warm water and the foaming ingredient added. This mixture is thenplaced in the outer tank. The chemical "A" is dissolved in hot waterand placed in the inner cylinder. The inner receptacle is then in-serted in the outer tank, the stopper slipped in place, and the wheelcap screwed tightly in place.
To operate the extinguisher the operator inverts it, thus permittingthe stopper of the inner cylinder to fall free and the "A" and "B"solutions to mix, and at the same time points the hose and nozzletoward the fire.
The chemical reaction develops about 40 pounds pressure and gen-erates a tough, durable foam which is expelled from the nozzle. Therange of the stream is about 30 feet, making it possible for theoperator to fight some types of fire from a safe distance.
EQUIPMENT 21
Carbon dioride.This type of extinguisher is a late developmentin equipment of this kind. It consists of a heavy-duty steel cylinderthat serves as a container for the carbon dioxide liquid, a screw-typedischarge valve that seals the liquid in the cylinder, an operatinghandwheel, a locking pin that holds the handwheel disengaged fromthe valve proper, a safety disk designed to rupture at 2,800 to 2,900pounds, a flexible reinforced hose, an insulated hose grip, a dischargetube, and a carrying handle.
The extinguishers are received from the manufacturer alreadycharged. The carbon dioxide in the cylinder, due to pressure whencharging, takes the form of a liquid, changing to a gas or a solid(carbon dioxide snow) as soon as the discharge valve is opened.
To operate the extinguisher it is either held or set firmly on theground. The operator then withdraws the locking pin from thehand wheel, thus permitting the hand wheel to snap downward andengage the stem of the discharge valve. The discharge tube is thenreleased and the hose grip held firmly in one hand while the dischargevalve is opened with the other hand, releasing a. cloud of gas andcarbon dioxide snow.
The discharge range of this type of extinguisher is limited to about5 or 6 feet; consequently, the operator must approach as closely aspossible to the fire.
MOUNTED EXrINCUISflERS
Large fire extinguishers (commonly called fire trucks) are used bysome mining companies. These extinguishers are mounted on mine-car trucks equipped with flanged wheels and designed to be hauled onthe mine track by a mine locomotive. Because of their large capac-ity, extinguishers of this type, if quickly available, are preferable tothe hand type for fighting fires of serious proportions.
The extinguishers are stored either on the surface or underground,depending on storage facilities and whether they are to be availablefor surface as well as underground use.
Large mounted extinguishers generally are of the soda-acid or foamtype. However, some of them are designed to use water instead ofchemicals.
Cheniical.One type of mounted extinguisher (fig. 8) consists oftwo soda-acid tanks having a capacity of 100 gallons each. Thetruck is equipped also with 200 feet of chemical hose having a nozzlewith a shut-off valve, two 1-quart, carbon tetrachloride, hand extin-guishers (or two 2½-gallon soda-acid or foam extinguishers), fiveall-service gas masks, one carbon monoxide detector, two gages forindicating pressure in the tanks, one floodlight, extra chemicalcharges, tools, etc. This extinguisher and equipment can be obtainedalso in the two 40-gallon-size tanks designed to use foa.mite instead ofsoda acid.
Water.At least one mining company has designed and is using amounted fire truck equipped to use water. This extinguisher (fig. 9)consists of a tank having a capacity of about 325 galIons of water.A pump and pipe connection to apply pressure to the water beingused from the tank furnishes a stream of considerable pressure. Thepump and connections can be used also to pick up water from eithera water hole or a. pipe and force it into the tank. The tank also canbe filled through a small opening in the top.
22 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
Q
EQUI1'MENT 23
The truck is equipped with 250 feet of 1½-inch linen-covered firehose with nozzle, five all-service gas masks, two 2½-gallon chemicalfire extinguishers, a roll of brattice cloth, a crosscut saw, picks, shov-els, slate bars, and other equipment and tools.
A reel containing a cable and mounted on one side of the tank canbe used to obtain electric current for operating the pump in advanceof trolley-wire installation.
Other types of mine fire trucks used by some companies areequipped with a number of various types of fire extinguishers, tools,gas masks, and materials for fire-fighting work. One company main-tains a fire trip composed of several mine cars equipped with a pump,brattice cloth, tools, gas masks, etc. This trip is stored at a conven-ient point underground and kept ready for emergency use.
Froua 9Water fire truck.
HOSE, NOZZLES, AND CONNECTIONS
An adequate supply of standard-size flue lìose in good conditionand with proper fittings, including several nozzles, should be avail-able at all mines for fire fighting. Special types of nozzles, such asperforated pieces of pipe closed on one end and threaded to fit a hoseconnection on the other end, are often of decided value in fightingunderground fires. Various sizes of connections, reducers, andadapters should be available to connect fire hose readily to all sizesand openings of pipe lines.
ROCK 1)UST
Rock dust can be used efficiently in extinguishing mine fires wlieiiit is possible to apply the dust directly on the fire, and numerousinstances are on record of the successful use of rock dust in combat-ting mine fires. A sufficient supply of rock dust in suitable bagsshould be kept available at all times for fire fighting and general use.
24 PROCEDURE IN SEALING AND UNSEAL1NG MINE FIRES
TOOLS
An adequate supply of hammers, axes, saws (hand and crosscut),sledges, hatchets, picks, shovels, bars, bricklayers' hammers andtrowels, pipe wrenches, and other necessary tools should be available.To minimize the likelihood of ignition of gas through sparks it isdesirable, if not imperative, that hammers, bars, etc., of copper orother relatively nonsparking material be provided for work beingdone in the presence of explosive gas.
TELEPHONES
Enough telephones always should be available at the base of opera-tions and at such other places as may be necessary to keep contactbetween those engaged in the recovery work underground andthose assisting in various capacities on the surface. After an explo-sion, as recovery work progresses, the telephone system should be keptin proximity to the fresh-air base at all times.
Under certain conditions the common types of outside and minetelephones can ignite an explosive mixture of gas. Therefore, per-missible-type telephones should be used in mines, especially duringrescue and recovery operations.
The Bureau of Mines, under schedule 9A,8 approved a mine tele-phone manufactured by the Western Electric Co. (approval 901) onJuly 16, 1927.
Portable telephones that operate without batteries have been de-veloped so that they can be used efficiently and satisfactorily forcommunication between oxygen breathing-apparatus or gas-maskcrews and the fresh-air base.
The equipment (fig. 10) consists of a receiver attached to a head setand throat transmitter and provided with a strap and worn by thecrew captain, being attached by a jack or plug to one end of about1,000 feet of light insulated cable. Tue cable is wound on a light metalreel, which is suspended and encased in a wooden frame. The otherend of the cable passes through the core of the reel and is attachedto two insulated commutators fastened on the outside of one of thereel flanges. Two bronze springs are in contact with the commuta-tors and connect, by an insulated wire, with a telephone jack attachedon the inner side of the frame.
A combination hand set, containing a transmitter and receiver, foruse of the man at the fresh-air base is connected ("plugged in") to thejack on the frame. A detachable crank for turning the reel and ashort chain with a snap for attaching the cable to a convenient placeon the oxygen breathing apparatus or gas mask worn by the crewcaptain complete the equipment. The transmitters of the telephonesare voice-energized and no electric current is used, which makes thistype of telephone equipment especially desirable for rescue and recov-ery work. It is possible with this equipment to conduct an ordinaryconversation satisfactorily through 2,500 feet of cable.
The captain of the crew attaches the cable to his apparatus by thechain and snap, places the head attachment over his head with the
Bureau of Mines, Procedure for Establishing a List of Permissible Telephones for UseIn Coal Mines: 5chedule PA, Dec. 5, 1922, 5 pp.
FIGUeE 10.Portable (batteryless-type) telephone.
MAPS
Mine maps, with the latest possible extensions of surveys, should beprovided as soon as possible after a mine fire or explosion. One ofthese should be posted in the general headquarters on the surface andadditional copies should be available for the men in charge of theunderground shifts, captains of oxygen breathing-apparatus crews,State mine inspectors, and others whQ may require a copy.
Some mining companies maintain a disaster map for emergencyuse, on which is noted the direction of ventilation in each entry, loca-tion of overcasts, doors, pumps, elevations, and other information.A map of this kind may be of much value after a fire or explosion.
EQUIPMENT 25
receiver over one ear, and straps the transmitter loosely around hisneck; while talking he holds the transmitter against his throat. Asthe mouthpiece of an oxygen breathing apparatus offers considerablehindrance to talking, the crew captain should reduce his conversationto a minimum.
A telephone system of this kind should be provided, as it willgreatly facilitate the work of oxygen breathing-apparatus and gas-mask crews where a life line is required and enable the man in chargeof tile fresh-air base to keep in communication with the crews workingahead of fresh air much more efficiently than if a life line were used.
26 PE0CEDItE IN SEALINQ AND INSEALTNQ MINE FIItES
L000MOTIVS, ANIMALS, AND CARS
To expedite the movemeiit of material, bodies, etc., after a minedisaster, means of transportation should be provided.
After a mine fire, it may be impossible or inadvisable to have elec-tric current in at least one section of a mine and probably the entiremine, and after an explosion all electric power should be cut off themine; it will be unsafe to use trolley-pole or cable-reel locomotives.
That there may be motive power for haulage purposes, permissiblestorage-battery locomotives or animals, such as mules or horses,should be provided. Enough mine cars in good condition should beavailable for transporting equipment, materials, bodies, etc.
ANALYTICAL APPARATUS
Analyses of mine-air samples may be highly important, and properfacilities should be provided for making them. For the quick deter-mination of carbon dioxide, oxygen, carbon monoxide, methane, nitro-gen, and probably hydrogen, a Bureau of Minestype, portable, waterOrsat apparatus with the necessary chemical solutions and electricalconnections should be available.
Although the portable Orsat apparatus is not highly accurate, it ispossible to determine, with careful operation, the percentage of thevarious gases to within about 0.20 to 0.30 percent. When greateraccuracy is necessary, laboratory-type equipment should be providedor the samples taken to a laboratory having apparatus of greateraccuracy.
PUMPS
Mine pumps of various designs and sizes should be available.Main pumps should be put in operation as soon as possible to preventflooding of the mine or sections of a mine. Field or gathering pumpsalso should be provided to remove water collected in places thatwould interfere with recovery work and to supply water for firefighting and other purposes.
CLOTHiNG
Rescue and recovery crews and other underground workers shouldwear safety clothing such as protective caps, shoes, goggles, gloves,etc. Members of underground crews should report to the mineequipped with proper clothing; however, it is very important thatextra supplies of gloves, socks, boots, shoes, caps, underwear, shirts,overalls, etc., should be available to provide clean, dry clothes forworkmen who get wet or damage their clothing.
MISCELLANEOUS EQIJIPILENT
Additional miscellaneous equipment and devices that may be re-.quired and should be provided as needed are anemometers, barom-eters, maximum and minimum thermometers, water gages, air-sam-pling tubes, oxygen inhalers, self-rescuers, stretchers, blankets, first-aid supplies, life lines for apparatus crews, mortar boxes, buckets,etc.
MATERIALS 27
MATERIALS
The materials required for conducting recovery operations to a con-siderable extent will depend upon local conditions and the nature ofthe work. Every expedient should be utilized in procuring andmaking available, when and where needed, the materials required toconduct recovery work efficiently. Lack of necessary materials willretard recovery operations unduly and also will add to the hazard ofthose engaged in the work. The following materials should be pro-vided as needed:
BRATTICE CLOTH
Brattice cloth will be required for temporary stoppings when amine fire must be sealed. If tlie area or mine involved in an explosionis extensive, a large amount of brattice cloth will be required fortemporary stoppings, line curtains, and other purposes. Severalkinds of brattice cloth, ranging from jute, the most commonly used,to heavy canvas, are obtainable. Some types have been treated tomake them more or less fire-resistant. An ample supply of thisimportant material should be available at all times.
LUMBER
An adequate supply of boards of various sizes, planks, two-by-fours,etc., should be provided as required for constructing semipermanentstoppings and doors, for repairing or rebuilding overcasts and airlocks, and for other uses.
NAILS AND SPIKES
An ample supply of nails and spikes of various sizes should beavailable. If numerdus stoppings are to be erected and other con-struction work is necessary, a large suppiy of nails will be necessary.Copper nails should be provided if work in explosive gas is required.
BRICK, CONCRETE BLOCKS, AND TILE
Bricks, concrete blocks, and tile, where readily available, are veryuseful for building permanent stoppings and overcasts following anexplosion and for erecting fire seals when a fire must be sealed.
PORTLAND CEMENT
Sufficient portland cement should be available for mortar whenbrick, concrete-block, and tile stoppings or other masonry work areto be erected and for more extensive use if concrete stoppings or otherconcrete work is necessary.
WOOD PIBER
Wood fiber in suitable bags should be provided for plastering tomake wood stoppings, doors, etc., as airtight as possible. Anefficient stopping can be erected with rough boards if the cracks andcrevices are plastered with wood fiber. The wood fiber should bemixed with water to the consistency of heavy mud and then appliedwith a trowel or the hands. Wood-fiber plaster sets quickly; there-fore, it is best to mix it at the place of use; and if acid mine water isused, it sets even more quickly.
61985-38------5
28 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
POSTS AND TIMBERS
A generous supply of mine posts, cap pieces, wedges, and heavytimber should be provided for roof support and for erecting canvasor board stoppings.
PIPE AND PIPE PITTINGS
Pipe of various sizes, with an ample supply of sleeves, elbows, tees,unions, reducers, valves, etc., should be provided for extending waterlines, for suction and discharge lines for pumps, and for other pur-poses as may be required.
WIRE, INSULATORS, HANGERS, ETC.
Proper types and sizes of wire, hangers, roof bolts, insulators, etc.,for telephone, signal, and power-transmission lines and for such otherpurposes as may be necessary should be provided as needed.
MISCELLANEOUS MATERIALS
In addition to the above, other miscellaneous materials, such asrock dust, ties, rails, frogs, switch points, track spikes, etc., andrepair parts for equipment, devices, and machinery should be pro-vided as required.
PROCEDURE FOLLOWING MINE FIRES
Proper procedure in fighting, sealing, and unsealing mine fires isof the utmost importance. Wrong procedure may result in one ormore of the following:
Men working in the mine when a fire occurs may be needlesslyexposed to or overcome by smoke and fumes from the fire.
An explosion with possible loss of life and property may occurduring the fighting, sealing, or unsealing operations.
The lives of those engaged in fighting, sealing, or unsealing amine fire may be jeopardized or sacrificed needlessly.
Property loss may be increased or curtailment of productionprolonged.
The destruction of life and property and the demoralization anddisorganization that frequently accompany mine fires cause themto be anticipated with dread by mining organizations. Mine firesare far more dangerous to handle than are explosions, unless theexplosion has left in its wake one or more fires; with an explosionusually the worst is over, but with a mine fire the worst is yet tobe feared. A tremendous toll in lives has been taken by asphyxiationor by explosions resulting from fires in mines, and unestimable prop-erty damage has resulted from them. As rocedure in fighting, seal-ing, and unsealing mine fires differs consicterably from that followedafter explosions, it is discussed under a separate heading.
No fixed rule can be laid down for the control and extinguishingof mine fires, for each fire presents a more or less original problem,depending on the çonditions encountered. However, it can be stateddefinitely that in any mine a fire is serious and dangerous, even ifthe mine or section of the mine in which the fire is liberates littleor no explosive gas; under mine-fire conditions normally nongassymines or sections of mines may become dangerously gassy through
The reader is referred to several papers on mine fires: Rice, G. S., Paul, J. W., andVon Bernewitz, M. W., Fifty-Nine Coal-Mine Fires: Bull. 229, Bureau of Mines, 1927, 156pp. Forbes, J. J., When and How to Unseal Mines Fires: Mining Congress Jour., July1927, pp. 512-519. Harrinoton, D., Lessons From the Granite Mountain Shaft Fire,Butte: Bull. 188, Bureau of 1lnes, 1922, 50 pp. Harrington, D., Pickard, B. O., Woiflin,H. M., Metal-Mine Fires: Tech. Paper 314, Bureau of Mines, 1923, 20 pp. Pickard, B. O.,Lessons From the Fire in the Argonaut Mine: Tech. Paper 363, Bureau of Mines, 1926,39 pp. Gregory, F. C., Fires and Fire Prevention in Lake Superior Mines: mf. CIrc.6073, Bureau of Mines. 1928 17 pp. Harrincton, D., Metal-Mine Fires and Ventilation:mf. Circ. 6678, Bureau of Mines, 1933, 31 pp. Harrington, D., Fene, W. J., Coal-MineExplosions and Coal- and Meta1-Mne Fires in the United States During the Fiscal YearEnded June 30, 1936: mf. Circ. 6927, Bureau of Mines, 1936, 17 pp.
PROCEDURE FOLLOWING MINE FIRES 29
distillations from the fire. Due consideration should be given tothe safest means of extinguishing any mine fire, regardless of theproperty damage or loss of equipment that may result. Frequently,efforts are made at considerable risk to fight fires directly, to preventinterference with production or to save equipment, when they couldbe sealed with little or no risk.
Although the information in this circular relating to the fighting,sealing, and unsealing of mine fires refers primarily to coal mines,most of it is applicable also to metal mines, with the possible excep-tion of that on explosive pses; however, explosive gases are foundsometimes in connection with metal-mine fires.
METHODS OF CONTROL AND EXTINGUISHMENT OF MINE FIRES
Methods of controlling and extinguishing mine fires are: (1)Fighting by direct attack, (2) sealing the fire area to exclude oxygen,(3) flooding the fire area or the entire mine, (4) flushing with silt orother solids, (5) use of incombustible barriers to prevent the spreadof fire, (6) using an inert gas, as carbon dioxide, and (7) unsealingthe fire area to recover bodies, to load out smoldering material, or tore-ventilate it.
FIGHTING MINE FIRES BY DIRECT ATTACK
Many mine fires are extinguishable in the inciient stage by directattack with water, chemicals, rock dust, or sanc. Failure to extin-guish fires by direct attack usually is due to late discovery, lack ofwater or means for applying it promptly, lack of fire extinguishersor other facilities, and improper procedure in the initial or subsequentattack.
In many instances prolonged efforts extending over several days,even weeks, are made to extinguish a fire by direct attack. Suchprocedure is usually accompamed by considerable risk to life andproperty and frequently is unsuccessful. Unless a fire can be ex-tinguished within a few hours by direct attack it is likely to be ad-visable to resort to some other method.
When mine fires are fought directly, the amount of air reaching thefire should be reduced to a minimum to prevent unnecessary intensi-fication of the fire; only enough air should be used to prevent smokeand fumes from backing up against the air current and to keep theintake side of the fire reasonably clear of smoke. Failure to ex-tinguish a mine fire by direct attack will necessitate an attempt atcontrol or extinguishment by some other method such as sealing,flooding1 flushing, etc. Although sealing is the most practical method,where direct attack fails or cannot be used, in some cases conditionsare such that sealing cannot be done effectively, and other methods
30 PROCEDURE IN SEALING AND IINSEALING MINE FIRES
such as flooding or flushing, may be preferable r even necessary.In some extreme cases sealing must be followed by flooding or flush-ing and that by the direct method of loading Out the flushed materialtogether with the heated strata, and in some cases this material ishandled by steam or electric-shovel methods.
USE OF WATER
If sufficient quantity and means of applicatioìi are available, wateris an excellent medium for the extinguishment of mine fires,especially in the early stages. As the fire increases, the water mustbe applied by hose and nozzles. Falls of roof and coal invariably willoccur as the fire progresses and make it difficult to apply water in themost effective manner. A perforated pipe or nozzle connected to ahose having a good head of water and controlled by a valve may bepushed gradually ahead into the active fire, and points beyond therange of ordinary nozzles may be reached; by using this methodthere is less hazard to persons from f allin rock, a large amount ofwater may be applied quickly and as quickly turned off, and lesssteam is likely to be formed.
Large quantities of water thrown directly on a fire of considerableextent and intensity, or water thrown on a mass of heated material,will form considerable steam and probably hydrogen. In the absenceof adequate ventilation, or as the result of a fall of roof, the steammay be forced on men or the hydrogen may explode with serious orfatal results.
Another method of more or less direct attack by water is to applyit to cool but not extinguish burning material, which is then loadedout by hand or more satisfactorily and speedily, by a loading ma-chine. Water is used also to wet the heated material thoroughlyafter it is loaded in cars to prevent the material from flaming duringtransportation.
USE OF CfIEMICLS
Direct attack may be made on mine' fires in the early stas bychemicals used in the various types of hand fire extinguishers.Larger fires may be fought successfully by large mounted chemicalextinguishers. Care should be exercised in using chemicals ex-tinguishers in confined places where there is little or no air move-ment, as some types of extinguisher (carbon tetrachioride) formdangerous fumes when thrown on a fire and others (soda-acid, foam,and carbon dioxide) form a heavy blanket of irrespirable gas.
USE OF ROCK DUST
Fine limeston ör shale dust for rock-dusting bituminous coalmines can be used successfully in fighting incipient fires as well aslarger fires under some conditions. In the early stages of a fire thedust is applied by hand or with shovels. As the fire progresses, theactively burning material often is partly covered by falls and therock dust may be poured on top of the fire and falls of smolderingmaterial. Rock dust not only serves to extinguish flame directly butexcludes air from burning material, thereby smothering the fire.Bock dust can be used also to cool heated material so that it can he
PROCEDuRE FOLLOWINC MINE FIRES 31
loaded more easily and to cover heated material loaded in cars andis preferable to water for such uses, as no steam is formed.
Some mining companies keep rock dust available for fire-fightingpurposes at various places throughout the mine.
USE OF SAND
Fine sand, if available, can be used in making a direct attack inessentially the same manner as rock dust; it is heavier, however, andtherefore harder to handle, and is usually loose, whereas rock dustgenerally is placed in sacks of convenient size for carrying andhandling
SEALING MINE PIRES
Mine fires should be sealed when progress cannot be made byfighting them directly or when other conditions, such as inaccessi-bility and probable dangerous accumulations of explosive gas, makesealing advisable. Temporary seals usually are erected in an effortto exclude quickly most of the air from a fire and later are supple-mented by airtight permanent seals.
Considerable difference of opinion exists as to which side (intakeor return) of a fire should be sealed first. Many mining men, in-cluding the authors, prefer to seal the intake and return airwayssimultaneously, especially if the fire is in a section of a mine whereexplosive gas is being liberated. If this is not feasible, because ofthe distance between openings, or for other reasons, it is advisableto seal the intake airways first. The reasons for sealing the intake-air side first are:
Unless it is being fanned vigorously by the ventilating cur-rent (which should not be done), the fire will travel mostly towardthe fresh-air or intake side. In some kinds of coal, the fire willtravel toward fresh air quite rapidly (almost as fast as a man canwalk); if the return side is sealed first the fire will burn longer,cover a larger area, and be checked little or none until the intakeside is sealed.
Ventilation around and over a fire consists of air from the in-take side, which, after being heated by contact with the fire, risesto the roof and leaves the fire by the return side; if little or no airis traveling in the ventilating current, the heat of the fire will createventilation and establish an intake and return air current.
As air comes in contact with the fire, much of the oxygen isconsumed, and the return side, therefore, generally is low in oxygenand the quickest way to diminish the oxygen, decrease the flame; aniprevent the fire from spreading is to seal the intake airways. Whenthe intake airways are closed, most of the air that the fire canobtain will be from the return side or air that already has passedover the fire and undoubtedly is low in oxygen and consequently willassist greatly in extinguishing flame and preventing an explosion.
The authors have assisted with the sealing of numerous fires ingassy sections of mines (some of them extremely gassy) and, unlessairways were sealed simultaneously, always have sealed the intakeairways first. Furthermore, Bureau of Mines engineers and safetyinstructors have assisted in sealing hundreds of mine fires (many ofthese in gassy mines), and, so far as known, at none of these havethe return airways been sealed first. In all of this work no serious
32 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
explosions occurred during the placìng of temporary seals. In someinstances explosions occurred some time after the seals were erected,but it is probable that they would have occurred, possibly withgreater frequency, if the return airways had been sealed first.
The distance from the fire at which seals should be built will begoverned by the nature of the roof and floor, the number of open-ings to be sealed, the condition of the air in the section involved,and whether the section to be sealed is gassy or nonassy.
In metal mines, or in coal mines where no gas is being liberated,the seals preferably should be placed as close to the fire as possible.By sealing close to the fire less area is involved, the oxygen di-minishes more rapidly, and the extinguishment of the fire is hastened.
Placing stoppings to seal a fire in a gassy section of a mine isdangerous and should be done with the utmost care and considera-tion; the seals should be placed as far from the fire as possible(1,000 feet or more) to allow considerable time to elapse before anexplosive mixture of gas is likely to be formed. A prominent engi-neer has described sealing a fire in a gassy section of a mine as arace to have the fire deplete the available oxygen before combustiblegases can accumulate to the explosive point.
An explosion invariably will occur if gas is given off in sufficientquantities to be within the explosive range of methane (5 to 15 per-cent) before the oxygen has been reduced below the percentage atwhich an explosion is possible (approximately 12 percent). Underthese conditions, it is advisable to erect tight temporary seals andthen withdraw all men from the mine for at least 24 hours beforeattempting to erect permanent seals. Furthermore, if an explosionis likely to occur after the temporary seals are erected, arrangementsshould be made to close the last seals after all men are out of themine This can be done by leaving hinged openings (doors), thatwill close automatically, in one or more of the stoppings and holdingthem open with a counterbalance in the form of a perforated bucketfilled with water; the perforations should be made so that sufficienttime will elapse ef ore the water drains from the bucket to allow themen in the mine to reach the surface before the door or doors closeto complete the temporary seals.
As a precautionary measure, it is advisable that a thick coating ofrock dust be applied to ribs, roof, and floor of entries, crosscuts, etc.,for several hundred feet outby and, if possible, inby the location oftemporary seals when fires are being sealed in gassy or dusty mines;hence, in the event of an explosion around the fire there will be littlelikelihood of propagating a coal-dust explosion. Although it maybe possible to seal a fire in a gassy section of a mine without a subse-quent explosion during or shortly after sealing operations, undoubt-edly the safest method is to seal the mine openings at the surface.
PEMPORARY STOPPINOS OR SFAI S
The element of time frequently enters into the construction of tem-porary stoppings or seals after a mine fire; the quicker they can beerected, the sooner air will be cut off the fire and the flame extin-guished. Therefore, readily available materials that require mini-mum time for construction should be used, provided, of course, theyare suitable to give the results desired from the sealing.
FIGuRE 11 .Brattice-c1oth stopping.
Brattice cloth.If it is necessary to erect a temporary stoppingquickly, or if it is not essential that the stopping be especially tight,a brattice-cloth stopping can be erected as follows: Select a suitablepoint and set a post near each rib, wedging it securely in place.Nail a board (6 to 12 inches wide and about 1 inch thick), extendingfrom rib to rib, across the top and bottom of the posts. Cut a pieceof brattice cloth large enough to cover the opening to be closed andhold it in place. Nail the. brattice cloth to the top and bottom boardsand, if possible, to the ribs. Complete the stopping by shovelingfine material along the bottom. Although a stopping of this typewill allow a certain amount of air leakage, it is tight enough formost purposes and can be erected in minimum time. Where timeis not a serious factor and a fairly tight stopping is required, orwhere the stopping must withstand considerable air pressure, amore substantial one of brattice cloth should be erected (fig. 11)as follows: Select a point where the roof and ribs are solid and
PROCEDURE FOLLOWING MINE FIRES 33
Tempórary stoppings or seals generally are constructed of bratticecloth or canvas, if available, because they can be erected quickly andcan be made fairly tight. If a more substantial stopping is desired,boards covered with brattice cloth or boards with pieces of bratticecloth, stiff mud, or wood fiber packed around the edges and in cracksand holes can be used. Except where stronger stoppings are neces-sary, wood is generally not as desirable as brattice cloth for tem-porary stoppings or seals. More time is required for construction,and unless the entire surface of a wood stopping is plastered it islittle, if any, tighter than a well-constructed brattice-cloth stopping.rfemporary stoppings should be set from 4 to 6 feet or more inside ofopenings to be sealed to allow room enough to erect permanentstoppings outby the temporary stoppings.
34 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
well squared and pick down all loose material. Set posts about ifoot from each rib and one or more posts (depending on the size ofthe opening) between the two rib posts. Be sure that the posts areset firmly and that where the floor is soft a mud cap or partial stillis set under each post. Nail suitable boards across the top, center,and bottom of the posts. The boards should extend from rib to riband the top and bottom boards should be placed as near as possibleto the roof and floor. If the ribs are .irregular, short boards extend-ing from the top to the center and from the center to the bottomboards, following roughly the curvature of the ribs, should be nailedalong both sides of the stopping. A piece of brattice cloth or canvaslarge enough to cover the opening to be sealed, allowing a smallsurplus on sides, top, and bottom, should be nailed to the boards.Additional layers or plies of brattice cloth, depending on the sizeof the opening, the air pressure against the stopping, and the thick-'ness and type of brattice cloth, should be nailed on top of the firstlayer to obtain a tight fit. To close small openings around the edgesof the stopping, wooden cleats (small pieces of boards) should beused to push the brattice cloth into all irregularities of the roof, ribs,and floor and should be nailed into place. To obtain maximum tight-ness it may be necessary to calk the edges of the stopping with piecesof brattice cloth or stiff mud or wood-fiber plaster and to shovel finedirt against and along the bottom. With reasonable care, a brattice-cloth stopping can be constructed that will allow only slight leakageof air.
Wood.If brattice cloth is not available for temporary stoppings,or a more substantial stopping is required, various kinds of boardscan be used. Usually, rough boards of various widths and about iinch thick are used, but for a tight stopping it is advisable to usetongue-and-groove boards. A wooden stopping is erected as follows:Select a suitable place and set, firmly enough, posts in the openinto be sealed. A shallow hitch should be dug in the roof, ribs, anfloor, and the boards fitted snugly into the hitch as the stoppingis erected. If tongue-and-groove boards are not used and sufficientbrattice cloth is available, the entire surface of the stopping shouldbe covered with a layer of the cloth. If brattice cloth is not avail-able, cracks or holes and places where boards are joined should beclosed with stiff mud or wood-fiber plaster. In either case, the edgesof the stopping should be calkeci with small pieces of brattice cloth,mud, or plaster. If carefully erected, a wooden stopping of thistype will be fairly strong and will allow a minimum of air leakage.
PERMANENT STOPPINGS OR SEALS
The character of the permanent stoppings or seals for sealinga mine fire depends on the materials available, the length of timethey are to be in use, the necessity for complete airtightness, andthe strength required to withstand pressure or crushing. Perma-nent stoppings or seals may be built of brick, cement blocks, concrete,tile, wood plastered with wood fiber, mud and cement, or cementmortar, wood with a layer or two of brattice cloth or tarred feltbetween layers of planks, or pack walls of various kinds.
Permanent stoppings erected for fire seals should be well hitchedin the ribs, roof, and floor and built snugly into the hitches to make
them as tight as possible. Provision should be made for collectingair samples, taking water-gage readings, and "bleeding off" excesspressure of fire gases by placing a pipe or pipes with suitable valvesin one or more of the stoppings. It may be advisable, also, to pro-
vide pipes and valves in some of the stoppings for the purpose offlooding or draining the fire area.
A pipe for collecting air samples may be placed anywhere in astopping, as, after the gases are diffused, the same mixture is likely to
61985-38 6
35PROCEDURE FOLLOWING MINE FIRES
36 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
be found anywhere behind the seals. For convenience, usually thepipe is placed near the center of the stopping. The number of stop-pings in which pipes should be placed for collecting air samples,etc., will depend upon the area under seal, the number of stoppingsused to seal the fire, and their position.
Permanent stoppings should be patrolled regularly, inspected fre-quently for leaks, and all leaks closed promptly.
Brick.Stoppings or seals constructed of brick (fig. 12) usuallyare satisfactory; brick withstands crushing about as well as anymaterial, and the size is well adapted to fitting into the irregularitiesof the ribs and roof. Brick stoppings should be 9 to 1 inches thick,according to the strength required. A strong cement mortar shouldbe used. One part cement to two parts sand will give great strengthand a 1-to-3 mixture will give a strong mortar for general use. Theaddition of 5 to 10 percent of hydrated lime will make the mortar
,j1 " .s!R-1e!Rock
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9" brick wall
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Fiuuu 13.Brick and tile stopping recommended by the National Mine RescueAssociation,
easier to work and probably quicker to set. After a brick stoppinghas been completed, the entire face of the stopping and the roof,ribs, and floor for a distance of several feet should be well plasteredwith cement mortar to prevent air leakage. The National MineRescue ii type of stopping is a modification of a brickstopping for fire seals (fig. 13). The important feature of this stop-ping is the tile section substituted for some of the bricks. Thissection is usually placed near the center of the stopping; it is 3 by 3feet (or larger if desired) and made of 5- by 8- by 12-inch back-uptile. The entire stopping should be well plastered with cementmortar. As it is difficult to make an opening in a solid brick wallthe tile center should be used in all stoppings that must be removedafter extinguishment of the fire through which inspection or explora-tion of the fire area may be made. The tile center can be knocked outeasily and, if necessary, the hole may be closed quickly with other tile.
10 The National Mine Rescue Association, formerly "Smoke Eaters" Association, is com-posed of men who actually have worn respiratory equipment during rescue and recoverywork lollQwing mine fires or exploslens. - - -
I,,- ---_----------_,_______l_______r- -#fd#'f_gF
PROCEDURE FOLLOWING MINE FIRES 37
38 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
Cement bloeks.Cement blocks laid with strong cement mortarmay be used to erect permanent seals or stoppings. The blocks arehollow and are not too heavy to be handled conveniently. Sizes are4 by 5 by 1 inches up to 12 by 12 by 36 inches and probably others.Ease of handling makes these blocks desirable. The tile center de-scribed for brick stoppings also can be placed in cement-block stop-pings.
Cement-block stoppings should be well hitched into the ribs, roof,a.nd floor to insure tightness; as the blocks may be somewhat porous,the surface of the stopping should be plastered well with cementmortar.
Concrete.Substantial stoppings may be made of concrete (fig. 14)they are durable, unaffected by water, have a high bearing strength,
FIGURE 15.Erecting a tile stopping.
and assist in supporting the roof. A form of rough lumber shouldbe erected at the point selected for the stopping and filled with con-crete mixture. 'When the concrete has hardened, the outside formshould be removed and all small openings or cracks filled with cementmortar. Concrete stoppings should be at least 6 inches and prefer-ably about 12 inches thick and well hitched into the ribs, roof, andfloor. 'Where the bottom is soft or has a tendency to heave, it maybe advisable to lay a foundation course of cement blocks at rightangles to the wall to obtain a larger bearing surface.
TiZe.A stopping or seal may be constructed more quickly of tile(fig. 15) than of smaller brick. However, tile will not bear muchweight without cracking or crushing and if subjected to pressure orsqueezing will not be satisfactory. The strength of tile stoppings canbe increased greatly by filling the tile with cement mortar and allow-ing it to harden before using the tile. Tile stoppings should be well
FIGURE 16.Board stopping plastered with wood fiber.
be nailed around the edges and the edges carefully packed with stiff-mud, wood-fiber, or mud-and-cement plaster. The entire surface ofthe stopping also should be covered with a fairly thick coating ofplaster. Suitable plaster can be made by mixing wood fiber andwater or mud and cement mortar to the proper consistency. Woodfiber and cement mortar are oenerally available and used. However,where suitable mud is at han, a mud-and-cement-plaster mixture hasadvantages as it apparently does not become as hard or crack asreadily as wood-fiber plaster or cement motar. An efficient mudplaster can be obtained by mixing 50 percent mud, such as is foundnear mine openings that have been flooded or Other suitable mud, and50 percent portland cement. Mud-and-cement plaster of this kindhas been used with satisfactory results.
In some instances plaster may not adhere readily to the smoothface of a wooden stopping, and roughening the surface of the boardswith a pick point will assist in making the plaster stick. The use
PROCEDURE FOLLOWING MINE FIRES 39
hitched into the ribs, roof, and floor, and it may be advisable to usebricks to fill in around the edges of stoppings. As tile is somewhatporous, the surface of stoppings should be well plastered with cementmortar.
Wood and plaster.If brick, cement blocks, tile, or material for con-crete are not available or an incombustible stopping is not required,permanent stoppings or seals may be erected with boards or plankand plaster. Numerous mine fires have been sealed successfully bywood and plaster stoppings. To erect a board and plaster stopping(fig. 16), firmly set enough posts in the opening to be sealed. Toobtain maximum stability, the posts should be set in hitches dug intothe roof and floor. Hitches should then be made in the roof, ribs, andfloor, boards fitted snugly into the hitches, and nailed to the posts untilthe stopping is completed. Tö seal the stopping tightly, cleats should
40 PIOCEDURE IN SEALING AND IJNSEALING MINE FIRES
of ship-lap boards in constructing the stopping provides a means ofholding the plaster in place. The boards are nailed to the posts likeclapboards on a house, but upside down. If ship-lap boards are notavailable, virtually the same effect can be obtained by nailing ordi-nary boards on the posts so that the upper edge of each board over-laps the bottom edge of the board above. This overlap offers arecess and support that will hold plaster much more effectively thanthe smooth face of a stopping.
Another efficient method for holding plaster or for placing addi-tional plaster on a stopping is to nail wire netting (chicken wire)over the face of the stopping, about 1 inch from the stopping, andthen apply a thick plastic coat of wood-fiber or mud-and-cementplaster.
Another type of wood and plaster stopping may be built of patentlaths (fig. 17), which are boards with grooves cut on one surface;the grooves will retain wood-fiber or other plaster effectively. Thestopping may be built as follows: Dig a hitch into the ribs, roof,
. / / , / '... / '. Double studs /
4 4 4;- - 44 ' # 44 s--4.4',v V.-..FIGURE 17.Stopping of patent lath plastered with wood fiber.
and floor at the point selected for the stopping. Cut a 2- by 4-inchcap, mud sill, and end studs to proper length. Set the bottom of theend studs on the mud sill, place the cap over the studs, and wedgethe cap securely in place. Toenail the studs. Place the other studsas shown in the sketch and double studs as indicated. Cut the patentlath to break joints on double studs on each side of the center, nailingthe lath on as cut. Cover holes around edges of stopping with shortpieces of lath, then apply a heavy coat of wood-fiber or mud-and-cement plaster.
A more substantial type of wooden stopping can be constructed byusing two layers of plank with a layer of tarred felt or bratticecloth between (fig. 18). Three or four posts should be set firmly inthe opening to be sealed, hitches should be dug into the roof, ribs,and floor, and a layer of plank 2 inches thick and of convenientwidth (usually 10 inches) should be nailed to the posts. Over thislayer of plank a layer of tarred felt or brattice cloth should be nailed,after which another layer of plank should be nailed over the tarredfelt or brattice cloth. The stopping should be completed by plaster-ing the edges with mud and cement or wood fiber. The entire face
2" by4" cap
" by 4" studs
7 2" by 4" silt
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An opening may be left in the stopping and a door, slightly largerthan the opening, constructed in the same manner as the stopping.The door is placed on the inside of the stopping, hinged at the top
PROCEDURE FOLLOWING MINE FIRES 41
of the stopping can be plastered also; however, this usually is notnecessary if the stopping is constructed properly.
42 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
with strap hinges, and fastened shut by bolts to plank crosspiecesplaced either vertically or horizontally over the door opening. Theorosspieces used to hold the door shut should have holes drilled inthem on the proper centers to fit over the bolts when the door is closed.The crosspieces should not be nailed but should be left free to shift,so that the holes may fit the bolts. When hinges are not available forattaching the door a strip can be nailed on the stopping below thedoor opening, on which the edge of the door can be placed to hold itin position while it is being bolted. After the door has been boltedin position the edges of the opening, where they meet the door, shouldbe well plastered.
Pack wall.A pack-wall stopping may be used for permanentstoppings or seals, especially in the absence of other suitable mate-rials. One type is constructed by setting two rows of posts, about 18inches apart, in the opening to be sealed. Hitches should be madeinto the ribs, roof, and floor. Boards should be nailed on the inbyrow of posts, and as the boards are nailed on the outby row of poststhe space between the boards should be filled with clay or loam.
If boards are not available, another type of pack-wall stoppingmay be constructed of rock with the space between the walls filledwith clay or loam. The outside wall should then be plastered to makethe stopping as tight as possible. It may be possible, also, to con-struct a single rock wall, well hitched and plastered, that will betight enough to seal a fire effectively.
If boards, rock, or other suitable materials are not available, or ifa strong stopping is necessary to withstand pressure, another type ofpack-wall stopping may be constructed by digging a long hitch intothe bottom, ribs, and roof and placing a layer of screened dirt severalinches deep in the bottom hitch, on top of which should be laid a rowof mine posts of fairly uniform size, parallel with the opening to besealed. The openings between the mine posts should then be filledwith screened dirt or loam, which should be well tamped between theposts, filled to several inches above the posts, and another layer ofposts added. The stopping is completed by alternate layers of postsand tamped dirt or loam. Such stoppings have been used success-fully in sealing several mine fires. Where the stopping will be sub-jected to excessive pressure or squeezing, this type often may be preferable to any other, as it becomes tighter and will not crack or breakunder pressure. Figure 19 shows various types of pack-wallstoppings.
FLOODING MINE FIRES
Occasionally a mine fire occurs where it may be extinguishedeasily if sufficient water is available to flood it, the water extinguish-ing the fire either by direct contact or by forming a seal and exclud-ing air.
In other cases, where explosions have occured or are occurringfrequently, making it extremely hazardous to fight the fire by directattack or to seal it, the fire area or entire mine may be flooded safeland the fire extinguishd. Also, after stoppings have been erecteto seal a fire area, flooding is sometimes employed to hasten extinguish-ment or to assist in excluding air when the stoppings, coal, or strataare not airtight.
A
I I II I
i i Outby side4 of stopping.II
i I
I
I I
I I
BoardsI - -
A]Posts and boards pack-wall stopping.
A'
Rock wall
AJRock and dirt pack.wall stopping.
A
Ii
Posts and dirt pack-wall stopping.
FIGURE 19.Sketch of pack-wall stoppings.
FLUShING MINE FIRES
Under certain conditions, flushing with silt or other solids is a de-sirable method of extinguishing a mine fire, especially where thearea or the mine probably will not be reopened or where the strata
SECTION A-A
SECTION A-A
PROCEDURE FOLLOWING MINE FIRES 43
Flooding is likely to be an expensive method of extinguishing minefires, as it usually requires considerable labor and material to intro-duce the water and to pump it out after the fire has been extinguished.Moreover, the effect of water on mine roof, equipment, etc., doubtlesswill result in much additional expense.
44 PROCEDURE IN SEALINO AND UNSEALING MINE FIRES
are so broken that neither sealing nor flooding is effective. Gen-erally, stoppings are erected to seal the fire area in so far as sealingcan be done, and then the area is flushed by introducing silt or othermaterial. The usual method is to suspend the ñne silt in water andflush the mixture of silt and water into the fire area through drillholes or otherwise. After the mixture reaches the fire area and itsmovement is arrested, the water drains off, allowing the silt to settleand fill most or all of the openings, thereby extinguishing the fire.This method has been used successfully in controlling sOme metal-mine fires.
USE OF INCOMBUSTIBLE BARRIERS TO PREVENT SPREAD OF FIRE
Incombustible barriers have been used successfully in several aban-doned coal mines to prevent the spread of fire. This method of con-trol is adaptable only where the barrier can extend from outcrop tooutcrop to isolate the fire. Briefly, the method is as follows: A tun-nel or open-cut, or both (about 12 to 20 feet wide), is cut throughthe coal bed from outcrop to outcrop and a safe distance from thefire. All combustible material is removed and the opening is com-pletely backfilled with incombustible material, usually clay or a mix-ture of sand and clay, flushed from the surface through drill holesspaced approximately 50 feet apart.
USE OF INERT GAS
Inert gas such as carbon dioxide (CO2) occasionally may be usedto advantage in cooling or extinguishing a mine fire; however, theuse of inert gas is an expensive, laborious, and often unsuccessfulmethod. If effective seals are erected and the fire area is airtight,enough inert gases will be produced by the fire and by the consump-tion of oxygen to extinguish the fire within a short time. If thefire area is not sealed tightly or no seals are erected, it is questionablewhether the use of inert gas, such as carbon dioxide, will be effec-tive. Where claims of the efective use of carbon dioxide have beenmade, it is likely that conditions have been especially favorable, asits use is known to have been unsuccessful in several attempts.
The usual method of using carbon dioxide is to allow it to flowfrom 100- or 200-cubic-foot cylinders on or over the fire, or to forceit through openings of fire-area stoppings. Another method is tobore holes into the fire area and introduce the gas through the holes.
Liquid carbon dioxide has been injected, under about 70 poundspressure, into the fire area through pipes in stoppings. It has alsobeen used by drivingperforated pipes into burning or smolderingmaterial and forcing it under pressure through the pipes. Recentlyit has been suggested that dry ice (solid carbon dioxide) under someconditions migt be used effectively in controlling or extinguishingmine fires.
UNSEALING MINE FIRES
The question of when and how to unseal mine fires is of vitalimportance to the mining industry. If a fire area is unsealed toosoon, the hazard to life and property is always increased; this dan-gerous practice has been followed and seemingly continues to be
t1N1IALINÙ MINE FItES 45
used with unusual frequency, with resultant loss of life and otherenormous economic losses. The premature opening of sealed minefires is due most frequently to lack of knowledge of the inherentdanger involved and to extreme eagerness to restore the sealed areato a prôduction basis. While material for this paper was being col-lected, it was discovered that State mining laws and authorities onmining give little information that would adequately assist thoseconfronted with this problem. This lack can be attributed largelyto the failure of mining men in the past to consider this problem asseriously as its importance merits. The control of fires by sealing andthe time for unsealing are based on established laws of physics andchemistry, as well as experience and sound judgment of surroundingcircumstances. Through the aid of chemists versed in the techniqueand interpretation of fire gases in sealed areas, a reasonably accurateknowledge of the composition of fire gases is available, and hencethere is opportunity to determine the potential hazard involved andwhen the seals can be broken with the least hazard.
Next in importance to determining the right time for unsealing isan efficient organization and ample provision for necessary equipmentand materials to be used by those who are to undertake this hazardoustask.
FACTORS GOVERNING TIME FOR UNSEALING
TJnsealing any mine fire is hazardous and should not be treatedlightly by those engaged in the work. Although a scaled area con-taining explosive gas undoubtedly presents the most dangerous con-dition, all mine fires should be considered as potential hazards whenthe time for unsealing them arrives. Besides making sure of theproper time for unsealing the fire area those engaged in the workshould be safeguarded in every possible way.
Experience and scientific study have shown that no attempt shouldbe made to unseal a mine fire (1) until the oxygen content of thesealed atmosphere is low enough to make explosions impossible, irre-spective of the amount of combustible gases or dusts that may be pres-ent, and () until the carbon monoxide (CO), the indicator f
com-bustion, has disappeared. In addition, the sealed area should begiven time to cool to minimize the chance of rekindling when air isadmitted. In substance, some of the principal factors that governthe time for unsealing fire areas, as gained from personal experience,observation, and consultation with experienced mining men are: (1)Extent and intensity of fire at time of sealing; (2) character of burn-ing material and overlying strata; (3) tightness of seals and enclosedarea; (4) influence of barometric pressure on the enclosed area; (5)position of the fire area with respect to ventilation; (6) samplingand analysis of the atmosphere under seal; and (7) composition offire gases in the sealed area.
EXTENT AND INTENSITY OF FIRE AT TIME OF SEALING
The extent and intensity of the fire at the time of sealing will havea decided bearing upon the reduction of oxygen in the sealed area.For instance, a large amount of burning or heated material willhasten the reduction of oxygen but will lengthen the time required
46 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
to cool; also, a fire that is active at the time of sealing will cause oxy-gen to diminish more rapidly than will a smoldering fire.
CHARACTERISTICS OF BURNING MATERIAL AND OVERLYING STRATA
The character of the burning material (that is, whether it is wood,bituminous coal, or anthracite), the rate of burning, and the changeof gas composition are factors that may influence rekindling whenair is again admitted. Coals that are high in volatile-combustiblematter burn faster and are more likely to rekindle when air is ad-mitted than are coals or material low in volatile-combustible matter.The character of the strata overlying the coal bed plays an impOrtantpart in determining the time for unsealing. For example, an oilyshale roof that presumably has covered a fire will retain heat for along time, even after the oxygen content of the sealed area is reducedto a point where combustion is impossible. There have been instanceswhere such a roof was hot 30 days after the oxygen content of thefire area had been reduced to below 3 percent. Under such condi-tions, the chance that the fire will be rekindled when air is admittedis increased considerably; furthermore, it is extremely difficult to getto the seat of the fire for a long time where the combustible roof hascaved and covered the fire. Another striking example of caved com-bustible roof materials aggravating the fire under seal is where thereis a coal roof or where the roof immediately over the coal is composedof alteriìate bands of bone, shale, and coal, some of which is fairlyhigh in sulphur. Combustile floor material also retains heat andtends to lengthen the period that should elapse before an attempt ismade to unseal.
TIGHTNESS OF SEALS AND ENCLOSE» AREA
Tight seals are essential for control of oxygen; preferably theyshould be made of incombustible material, such as brick, tile, or con-crete, well hitched into ribs, floor, and roof. They should be builtwhere the roof as well as the floor and ribs are sound, to reduce to aminimum leakage through the strata. Seals cannot be made com-pletely airtight, but an effort should be made to make them as tightas possible. If there are excessive leaks around and through theseals or if there are cracks or breaks to the surface or overlyingmeasures, effort to control oxygen and extinguish the fire will befutile. There should be a constant decrease of oxygen content in thesamples collected from behind fire seals; and if this does not occur,it usually can be attributed to leaky stoppins or breaks in the strataor coal that permit ingress of air. Sometimes the oxygen will bereduced rapidly and consistently and then, with slight fluctuations,remain almost stationary. This condition, also, usually can be tracedto the same cause. In both cases the stoppings should be examinedcarefully and an extra effort made to close any leaks. If the stop-pings are leaky or the fire is likely to burn around stoppings thathave been erected, it may be advisable to erect double stoppings.When double stoppings are erected, if possible they should be about15 or 20 feet apart. Stoppings should be inspected frequently andany cracks in or around them repaired promptly. Provisions shouldbe made for collecting air samples and taking water-gage readings by
UNSEALING MINE FIRES 47
placing pipes with suitable valves, reducers, etc., in one or more ofthe stoppings.
INFLTJENOz OF BAROMFrEIO PRESSURE AND TEMPERATURE ON ENCLOSED AREA
Barometric pressure has an effect on sealed areas, as it is largelyresponsible for the so-called "breathing" in and out. If barometricpressure increases in excess of the pressure behind seals, air is likelyto enter the sealed region. Similarly, if barometric pressure de-creases to less than that of the sealed region outward, leakagethrough or around the stoppings will result. The latter conditionassists materially in reducing the oxygen and aids dissipation ofcarbon monoxide. Frequently sufficient pressure is developed in theenclosed region to offset any increase in barometric pressure, andwhen these ideal conditions prevail there will be continual outwardpressure against the seals. Facilities for taking water-gage observa-tions should be provided in one or more of the stoppings that enclosethe fire region. When the water gage indicates that pressure is in-creasing in the fire region, the excess pressure. may be "bled off"under a water seal if it is found advisable to do so.
The temperature on the outside of the mine probably has moreinfluence than the barometric pressure on a sealed fire region. It isknown, from observation, that when the temperature outside of themine is considerably lower than the mine temperature, inward pres-sure on the fire seals is likely to occur, and that if the outside tem-perature is soniewhat higher than the mine temperature outwardpressure will result.
It is not known definitely what causes outside temperature changesto affect the pressure on a sealed fire area, but it is well known thatincrease or decrease in the temperature of gas or air will result inincrease or decrease in volume and pressure. Therefore, it is logicalto assume that warming or cooling of the outside air as it circulatesthrough the mine causes increase or decrease in volume and pressure,which, in turn, results in either inward or outward prèssure (inwardif the outside temperature is lower and outward if it is higher) onthe stoppings of a sealed region.
The temperature within the sealed territory also probably has con-siderable influence on the direction of pressure (inward or outward)on the stoppings. When a fire is extinguished within a sealed regionand cooling progresses, there is a decrease in volume and pressureinside the sealed region, which undoubtedly will cause inward pres-sure on the stoppings until the inside and outside pressures areequalized.
Temperatures at the site of seals are not indicative necessarily ofthe temperature within the sealed territory; however, if any of thestoppings are hot or warm, it is evident that the temperature withinthe sealed region is high.
EFFECT OF VENTILATION ON SEALED AREA
The location of the fire region with respect to the system of ventila-tion may have considerable effect on the extinguishment of a fire.For example, an area sealed where t.he air current passes on twosides (one side being intake and the other return) as against an area
48 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
sealed on one side only (such as a pair of entries) will cause a differ-ence in potential that may induce leakage through the stoppings andstrata. A condition of this sort may prolong the extinguishment ofthe fire. The fire at the Oakmont mine of the human Coal & Coke
u
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FIQURF7 20.Sealed fire area In the Oakmont mine.
Co., in Pennsylvania, which is referred to later, is a striking exampleof how circulation of air through the sealed area prevented extin-guishment of a fire for approximately 6 months because differentparts of the sealed pane.l (fig. 20) were under different amounts ofsuction or negative pressure. From figure 20 it can be seen that an
' Yant, W. P., and Berger, L. B., sampling Mine Gases and Use of the Bureau of MinesPortable Orsat Apparatus in Their Analyses: Miners' Circular 34 (revised), Bureau ofMInes, 1930, 90 pp.
UNSEALING MINE FIRES 49
entire panel was sealed and that it was possible to travel and makeobservations on all sides of the sealed region.
The seals enclosing the fire region consisted of 13-inch brick wallslaid in cement mortar, exceptionally well hitched in the roof, ribs,and floor, and as nearly airtight as stoppings ordinarily can be made.When a consistent reduction of oxygen did not occur, doublestoppings were erected along the main face entries, but this had littleor no effect. As indicated by arrows on the sketch, when the regionwas sealed the ventilation consisted of an intake air current from onesplit traveling along the stoppings on the main face entries and thetop of the sealed panel and a return air current from another splittraveling along the opposite side and bottom of the panel. The dif-ference in potential between the two air currents was about 3 incheswater gage.
Under the conditions described, the oxygen was not reduced below4.20 percent for about 6 months. A change was made in the ventila-tion by erecting a stopping and opening a door (indicated on sketchby circle in lower right hand corner), thereby taking air from thesplit on the main-face entries around the opposite side and bottomof the sealed panel as well as along the main-face entries and top ofthe panel; the result was that the same air pressure was exerted on allsides of the sealed region, and a gradual and consistent reduction ofoxygen to below 1 percent followed in about 4 months. Furtherdetails on the oxygen content and other gases within the sealed terri-tory are discussed later in this publication.
SAMPLINO AND ANALYSTS OF ATMOSPHERFI UNDER SEAL
It is of the utmost importance that proper sampling and accurateanalyses be made of the fire gases so they indicate unquestionably thecomposition of the gases in the sealed area. Samples should be col-lected from behind stoppings only when the pressure is outward, assamples collected when there is inward pressure almost invariablyare inaccurate and consequently are not representative of the sealedatmosphere. Samples from fire areas should be collected at least onceevery 24 hours during the first few days. Later, when the analysisshows by the reduction of oxygen that the stoppings are tight, thesamples can be collected at longer intervals, possibly once a week oreven longer.
There are at least three methods that can be employed in collectingsamples 11by vacuum tube, water displacement, and air displace-ment (using an aspirator bulb or pump). Of the three methods, thevacuum tube is preferable, as it is more easily sealed, can be storedalmost indefinitely, and is best adapted for shipment. After sampleshave been collected they should be analyzed accurately. Portablefield apparatus can be used where extreme accuracy is not essential.The portable modified Orsat apparatus is accurate to approximately0.20 in the reading of the percent by volume of the gases analyzed.If greater accuracy is desired, the samples should be sent to a labora-tory equipped for accurate work, where analysis as accurate as 0.01or 0.02 can be made.
50 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
c0MPOSrL"ION 0F E GASES IN SEALED AREA
Correct interpretation of the composition of fire gases is vital indetermining when it is reasonably safe to break the seals. It haslong been recognized that the presence of carbon monoxide indicatesactive or recently active fire; the absence of carbon monoxide is not asafe criterion that the fire has been extinguished, but rather thatflame and more or less active combustion have ceased. Especiallydoes this hold where a large area is under seal, in which case carbonmonoxide may be lost through dilution or may not be diffusedthroughout the entire territory. It is not safe to unseal any fire,with a view to ventilating the affected region, until the carbonmonoxide has disappeared. Even after the carbon monoxide hasdisappeared it is advisable to allow ample additional time for theheated, material and strata to cool before the sealed area is openedand ventilated; in fact, it may be necessary to delay unsealing forseveral months before the region cools enough to be reopened withsafety.
Although few if any scientific data are available, it is generallyrecognized that at least three causes contribute to the diminution ofoxygen within a sealed territory. These are displacement of oxygenby methane emissions from the coal or strata, absorption of oxygenby exposed coal surfaces and timber, and consumption of oxygen bycombustion.
Before an attempt is made to unseal a fire, the oxygen in the sealedregion should be low enough to prevent the possible ignition of ex-plosive gases; but before this condition obtains, active combustionnaturally will have ceased. In their experiments with methane-airmixtures, Jones and Perrotthi found that when the oxygen is reducedto 12.1 percent flame propagation and explosion are impossible, riomatter what proportions of methane are present. The gases foundin sealed regions contain, in addition to varying percentages ofmethane, small quantities of hydrogen, carbon monoxide, and othercombustible gases. The extent to which oxygen should be reducedunder these conditions depends upon the relative quantities of hydro-gen, carbon monoxide, and other combustible gases present. Thedata available on this subject indicate that when the oxygen in asealed fire territory is reduced to 4 percent, there is little if anylikelihood of an explosion. However, it is desirable that the oxygenbe reduced to at least 3 percent and preferably below 1 percent beforean attempt is made to unseal as the lower the percentages, the greaterthe safety from dilution o the gas due to changes in barometricpressure or leaks during unsealing.
The influence of carbon dioxide contained in fire gases is shown byCoward and Hartweil'3 who have determined that 25 percent ormore of carbon dioxide is required to render methane-air mixturesincapable of flame propagation. They also found that there was amarked decrease in the upper explosive limit (15 percent) of methane-air mixtures and a comparatively slow increase in the lower limit (5
Jones, G. W., and Perrott, G. St. J., Oxygen Required for the Propagation of Ilydro.gen, Carbon Monoxide, and Methane Flames: Paper read before spring meeting of Ameri-can Chemical Society, Richmond, Va., Apr11 13, i927. Coward, H. F., and Joues, G. W..Limits of Inflammability of Gases and Vapors: Bull. 27.9, Bureau of Mines, i928, 99 pp.
15Coward, H. F., and Hartwell, F. J., The Limits of Inflammability of Fire Damp InAtmospheres Which Contain Black Damp: Safety in Mines Research Board Paper 19,London, England, 1926.
Sam-pie
Date,1926 Hour Location
Percent by volume Watergage
in stop-ping
Barom-eter inmineCO2 Oa CO cn4 Na
Incfs I,iche&1 Feb. 5 12 noon_ .. 8-face stopping 2. 4 13. 4 0. 8 11.3 72. 12 ..,,do 4:45 p.m do 2.8 12.3 1.3 11.7 72.93 - do 11:30 p. m_ do 3. 0 11. 3 1. 3 13. 1 71. 34 Feb. 6 5:30 a. m - do 4. 1 9. 8 1. 4 15. 8 68. 9S .do 12 noon do 4.5 5.9 1.4 18.2 67.0 0.76 _do 6:45 p. m... do 4. 7 8. 3 1. 6 19. 4 66. 0 .65Z -- do 11:45 p. m do 4. 6 8. 0 1. 4 20. 5 65. 5 .78 Feb. 7 8:45 a. m - do 5. 2 7. 0 1. 6 23. 1 63. 1 . 79 -- do 4:45 p. In do 4. 7 6. 4 1. 4 24. 9 62. 4 1. 2
10 _....do 11:05 p. m do 4. 5 6. 2 1. 5 26. 6 61. 2 2. 311 Feb. 8 3 a. in do 4.6 6.1 1.5 27.8 60.0 1.45 29.2512 .,do 11:05 a. m do 4.6 5.5 1.5 29.9 58.5 1.8 29.1713 .....do 5:SOp,m do . 4.6 5.2 1.4 30.7 58.1 LS
UNSEALING MINE FIRES 51
percent) by the addition of varying percentages of carbon dioxide.The practical application of these experiments is to show that theexplosion limits of methane-air mixtures in mines are unaffected bycarbon dioxide and that the latter has little, if any, influence, otherthan the displacement of oxygen, in the extinguishment of a fire underseal because the percentage of carbon dioxide found in fire gasesrarely exceeds 6 percent at the time for unsealing.
TYPIcAL EXAMPLES OF MINE-FIRE GASES
Tables 1 and 2 give analyses of fire gases taken from the Horningand Oakmont mines near Pittsburgh, Pa.
HoriiiHg imine.-On February 5, 1926, a section of the Horningmine of the Pittsburgh Terminal Coal Corporation, Pennsylvania,was sealed following a fire and two subsequent explosions. It will benoted from table 1 that the first sample, taken at noon on February 5,showed 13.4 percent of oxygen. Subsequent samples taken at f re-querit intervals showed a constant and somewhat rapid reduction inthe oxygen content from the first sample to No. 17 (4.2 percent) col-lected 10: 50 p. m., February 9. This reduction from 13.4 to 4.2 per-cent probably was hastened by a gas feeder which was the source ofthe original fire and the subsequent explosions. The gas issuing fromthe feeder caused increased pressure in the enclosed area, which inturn reduced the oxygen content in the air by outward leakage of theatmosphere under seal through the stopping that enclosed the fire.This is clearly brought out by a study of table 1, which shows 11.3percent of methane on February 5 and 33.6 percent on February 9.Recovery of the affected region was begun by a system of air locks onthe 10th and completed on the 15th. The maximum oxygen increaseduring this period, while rescue crews were at work, was only 1.4 per-cent, and the methane increased from 34.2 to 51.3' percent. Seals wereplaced in the entry where the fire originated on February 15, and noattempt was made to ventilate the affected region until March 13. Atthis time the oxygen and carbon monoxide contents were 0.2 and 0.1percent, respectively. An exploration trip by rescue crews on March13 proved that the fire had been extinguished. A full account of thisoccurrence is given under "Procedure used in unsealing Horning minefire."
TABLE i -Analyset of air samples taken at the Horning mine fire and eccplo.9iOn(fire and enplosion. occnrred Feb. , 192G)
52 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
TAELn 1.-AnalyHis of air samples taken at the Horning mine fire and eplosion(fire and evplosion occurred Feb. 3, 1926)-Continued
i Seals were broken about 4 hours after sample 17 was taken.2 Last body recovered on Feb. 15 at 11:03 p.m.
Sample 37 taken 25 days after recovery of bodies.'Sample 38 taken 27 days after recovery of bodies.2 Seals broken and area ventilated night of Mar. 13, 1926.
Oaknwnt mine.-On January 14, 1925, a section (see fig. 20) of theOakmont mine was sealed following the discovery of fire. It will beobserved from table 2 that the first sample, collected on January 15,contained 15.45 percent of oxygen and another sample, collected onthe 24th, contained 4.2 percent. This was the lowest oxygen contentshown over a long period, as a sample collected on March 6 contained5.2 percent. When the oxygen content showed no reduction, the stop-pings surrounding the fire area were reinforced and every effort wasmade to stop leakage of air. Water-gage readings taken at the stop-pings on the intake and return sides of the area showed about 3 inchesinward pressure on the intake side and about 3 inches outward pressureon the return side. On April 4, in order to ascertain definitely condi-tions within the sealed area, rescue crews explored behind the sealsadj acent to the fire. The explorations were made through air locksA and B, thus admitting a minimum amount of oxygen. When the
Sm Hour LocationPercent by volume Water
ping
Barom-
002 0, CO 0114 N,
Inrhes Inche.s14 Feb. 9 1 a. m 8-face stopping 4. 5 5. 0 1. 3 33. 0 56. 2 2. 25 29. 1115 - do 11 a. m_.... do 4. 6 4. 7 1. 3 34. 5 54. 9 1. 2 28. 8f16 do 6:10 p. m - do 4. 3 4. 4 1. 1 36. 1 13. 7 . 9 28. 71
'17 - do 10:50 p. m_ do 4. f3 4. 2 1. 5 36. 5 53. 2 1.0518 Feb. 10 3:45 a. m do 4. 0 5. 7 1. 3 31. 6 55. 419 .do----- 6 a. m 160 feet inby seal on
ninth face.3.6 4.2 1.6 34.2 56.3
20 ..do 8:40 a. m.. Where stopping No. 3is built.
3.7 3.9 1.3 38.7 52.4
21 ....do 10:20 p. m No. 3 stopping afterstopping was built.
3.8 5.5 1.3 36.3 13.1
22 - - do-------- do No. 2 stopping afterstopping was built.
3. 8 5.6 1. 2 36.3 53. 1
21 ..do lip. m_.. From valve in 8-facestopping.
4.0 3.9 1.6 41.1 49.3
24 Feb. lI 7:lOa. rn... Ninth face 27 feet inbybreakthrough No. 7.
4.2 3.6 1.4 43.8 47.0 .2
25 _....do lia. m_.... From valve in 8-facestopping.
3,9 3.4 1.3 44.8 46.6 .3 29.31
26 _..do 11:45 a. m Ninth face 15 feet inbycrosscut where No. 7stopping is to be built.
4.0 3. 5 1. 2 43.8 47. 5
27 -- do-------- do Eighth face 15 feet inbycrosscut where No. 7stopping is tube built.
4.0 3. 5 1.3 41. 3 47.9
28 Feb. 12 12:11 a. m Ninth face 15 butt firstadvance.
4.0 3. 2 1. 4 46. 6 44.8
29 Feb. 13 4:45 a. m.... 15 butt between Nos. 1and 2 rooms. -
3.5 4.5 1.2 44.6 46.2
30 _....do 9:10 a. rn. - Outside stopping in 16butt.
3. 1 4.8 1. i 46.4 44.2
31 do i p. m....... 15 butt between Nos, iand 2 rooms.
3.6 4.8 1. 1 45. 5 45.0
32 ..do Sp. m Intersection of No. 2room 15 butt.
3.5 4.7 1.0 45.1 45.3
33 _....do 10:30 p. m. Inside chute 16 butt 100feet from face.
3. 1 4. 6 . 7 46. 5 45. 1
34 Feb. 14 2 a. m 6 feet inby last crosscuton 16 butt.
3.i 5.6 .9 45.6 44.8
35 - - do 10 p. m.._ 15 butt upper chute 2. 8 6.0 - 4 46. 2 44. 6236 Feb. 15 5:10 p. m... Eighthface 250 feet inby 2.5 4.7 .1 52.8 39.5
16 butt.537 Mar. 11 1:30 p. rn... Through seal 16 butt...... 2.9 .1 .1 88.8 8.1'38 Mar. 132 7:40 p. m. do 2.8 .2 .1 88.8 8.1
t Seals broken and area ventilated night of Oct. 15, 1925.
CONCLUSIONS REGABDING TIME TO UNSEAL FlEES
In addition to the factors just mentioned, which generally govern thetime for unsealing, there may be local factors that will necessitate care-ful scrutiny, such as the proximity of gas wells to fire areas, the posi-tions of boreholes, the extent of the region under seal, and tempera-ture within the sealed area. Ordinarily, more. time. will be requiredbefore unsealing a large area than a small area; especially is this trueif the seals in the former are poorly placed.
UNSEALING MINE FIRES 53
rescue crew found unmistakable indications of fire within air lockB, the area was resealed and flooded. The flooding was afterwardsfound to have been unsuccessful, owing to differences in elevationwithin the sealed area. Table 2 shows that after resealing, samplescontained slightly more oxygen, and virtually no reduction was effecteduntil after July 10. The increase in oxygen probably was due largelyto water being pumped to the sealed region. The carbon monoxidedid not decrease materially until after June 11. On June 12 theventilation was changed by building a stopping in the return fromNo. 10 butt and by opening trapdoor E on the intake airway outby No.10 butt. The change in ventilation placed an equal pressure on allstoppings that enclosed the fire region, and the water-gage readings atall stoppings became zero. The carbon monoxide also began to de-crease rapidly. A sample taken on August 22 showed 2.1 percent ofoxygen, and samples taken on October 8 showed 0.8 percent at No. 20butt and 0.4 percent at No. 10 butt, respectively. On October 15 theterritory was explored and, as no indications of fire were found, itwas reventilated.
TABLE 2.-Anaty8es of air sampe taken in Oak.rnont mine sealed area (firediscovered Jan. 14, 1925)
Sam.pie
Date,1925
Location,butt No.
Percent by volume
emar sCO2 02 112 CO Cil4 N2
1 Jan. 15 l9return..... 2.22 15.45 0.0 0.66 1.44 70.23 First sample after stoppings wereoosnpieted.
2 Jan. 24 do 4.5 4.2 1.4 1.2 3.8 84.9 Jlydrogenprobablyduetoburningmaterial failing in water.
3 Feb. 9 ..do 4.8 5.5 .6 1.4 5.4 82.34 Feb. 26 do 5.4 4.9 .0 5.6 7.1 81.05 Mar. 6 ..do 5.2 5.7 .0 1.1 7.3 80.7 Explored back of stopping, Apr. 4,
1925.6 Apr. 8 do 5.8 5.5 .0 1.1 7.9 79.5 Star66d to flood behind seals.7 Apr. 16 10 return... 3.7 5.8 .0 .4 8.6 81.5 Unable to get sample at 19 butt
closed by water.S .do 20 intake_ 5.0 6. 1.. 0 .8 8. 3 79. 8 Large volume of air pumped outbefore taking sample.
O May fi 10 return... 3. 8 6. 1 . 0 .3 9. 2 80. 610 ....do 20intake_ 3.5 7.5 .0 .4 10.5 78.1 Do.11 June 11 10 return...... 2.4 5.6 .1 .1 10.7 81.2 ilydrogen probably due to wate
reaching fire in roof.12 do 20 intake 1.9 8.5 .6 .0 18.5 68.5 Do.13 June 22 10 return..... 2.7 7.7 .0 .05 11. 1 78.4714 - do 20 intake..... 3. 8 6. 1 . 0 .0 19. 8 70. 3 Considerable pumping to get sam-
ple.15 July 10 lO retUrn...... 3. 1 6. 9 .0 Tr. 10. 7 79. 336 - - do 20 intake. 3. 1 4. 7 0 Tr. 18. 6 71. 6 Stopping under pressure.17 Aug. 22 10 return 4.3 2.1 .0 .0 17.1 76.518 Oct. 8 do 4.6 .8 .0 .0 20.8 73.819 ...do 20 intake..... 3.3 .4 .0 .0 26.4 69.9 Do.
54 PROCEDURE IN SEALING AND IJNSEALING MINE VIRES
Very careful consideration obviously must be given to all of theforegoing factors in the proper determination of the time for unseal-ing, as an error in any of them may necessitate resealing and mayresult in disaster.
PREPARATICN FOR TJNSEALING
The successful opening of any fire area necessitates certain prepara-tory work; an organization composed of oxygen breathing-apparatusand gas-mask crews and other necessary personnel, with the equip-ment and material required, should be assembled and ready for work.Most certainly no person should be in the mine during unsealing exceptthose engaged in the work and absolutely needed.
VENTILATION AN!) ROCK DUSTING
Necessary adjustments in ventilation should be to direct fire gasesfrom the sealed region into the main return. All return airways thatare to be utilized for carrying the fire gases to the outside of the mineshould be inspected carefully and necessary arrangements made toconfine the gases therein and prevent their circulation or accumulationin other portions of the mine. In bituminous coal mines all entriesand crosscuts leading to and from the fire region should be coatedheavily with rock dust at and for a considerable distance outby theseals that are to be opened.
FAN AND FAN ATTENDANT
An attendant should be at the mine fan to see that it is operatingefficiently, and if its slows down or stops, immediately to warn themen engaged in the unsealing work. If the fan is electrically driven,gases from the sealed region should be prevented from coming in con-tact with the motor or other electrical equipment used for operating thefan. Guards shodid be placed to prevent smoking in the vicinityof an exhaust fan and to prevent unauthorized persons from approach-ing the fan while fire gases are being moved, or any opening fromwhich fire gases are issuing when a force fan is used.
ELECTRIC POWER CU'r-OUT
It is essential that electric power be cut off the section of a coalmine in which a fire is sealed even before the actual work of unsealingis undertaken. Moreover, when the seals are opened, it is absolutelynecessary that the electric power be cut off from at least the sectioncontaining the fire and the return airways to obviate possible ignitionof gas through arcs or sparks. Where possible, it is highly desirableto cut all electric current from the entire mine during unsealingoperations.
METHODS OF UNSRATJNG MINE FIRES
The method to be used for the recovery of a fire region must beplanned and outlined in detail before the seals are broken. In general,two systems may be employed (1) recovery in successive blocks bymeans of air locks and (2) reventilation after there is conclusive evi-dence that the fire has been extinguished When the sealed area isextensive, the fire inaccessible, or the exigencies of the case necessitatethe removal of bodies from a previous explosion, the region should e
14 Alien, C. A., and Watts. A. C., Apparatus Men Load Out Heated Material From aMine Fire in a Cooling Current of Oxygen-Depleted Air: Coal Age, vol. 21, Mar. 23, 1922,pp. 479-483.
UNSEALING MINE FIRES 55
recovered in sections by using air locks and advancing to a point whereobservations can be made or the bodies recovered. Air locks consistof two stoppings 10 or 15 feet apart equipped with doors throughwhich oxygen breathing-apparatus crews can enter or take materialinto the sealed area. One door of the air lock is kept closed at alltimes. After an air lock is completed, the crews work through it anderect another air lock about 200 to 500 feet inby and perform suchother work as may be required for reventilation of the region betweenair locks. The distance between locks depends largely on conditionsencountered, such as ease of travel, height of passageway, work to bedone, etc. As an area between air locks is recovered, the locks outbyshould be removed. After the air locks have been advanced closeenough to the seat of the fire to permit observations to be made, it maybe possible to load out heated material through the air locks, as wasdone at the Sunnyside mine, Sunnyside, Utah.14 When the areaunder seal is relatively small, so that it can be explored by rescuecrews under reasonably safe conditions and when there is every indi-cation that the fire has been extinguished, the region should be reven-tilated and the fire gases removed as quickly as possible, preferablywith all persons out of the mine.
RECOVERING SEALED RECION BY USE OF AIR LOCYS
If it has been decided to recover part or all of a sealed fire area bythe use of air locks, a tightly constructed air lock should be erectedat a convenient distance from one of the seals on the intake side of thefire area.
After the oxygen has been reduced considerably below the pointwhere an explosion is possible, if explosive gas is being generatedwithin the sealed area, or below the point where a flame can burn, ifno explosive gas is present (12.10 and 1.25 percent, respectively), air-locking operations can be started. To provide an adequate safetyfactor, before the seals are broken the oxygen should be reduced atleast to percent when explosive gas is present and at least to 10percent or lower when no gas is present.
After a suitable air lock has been erected, proper organization andadequate equipment and material have been provided, and all othernecessary arrangements have been completed, an oxygen breathing-apparatus crew fully equipped for the work at hand and supportedby a fully equipped reserve crew should enter the air lock and removethe seal.
After the seal has been removed, an advance oxygen breathing-apparatus crew with another crew in reserve, using a life line orportable telephone, should explore to the point where the next airlock is to be erected, a distance generally not to exceed 500 feet. Thisexploring crew should observe general conditions, take temperaturereadings, collect an air sample to check previous analyses, measurefor material required to construct the inby stopping of the next airlock, and then return to the fresh-air base. An apparatus crew orcrews, with a reserve crew at the fresh-air base, should construct astopping with a door in it at the place previously selected for the
56 PROCEDU1IE iN SEALING AND UNSEALING MINE FIRES
next air lock; should erect necessary stopping in crosscuts or otheropenings on the intake side and on the parallel entry or entries onthe return side opposite the point selected for the air lock to insureresealing of the inby area; and should examine any unexplored partsof the isolated area for possible fires. Then crews should be with-drawn from inside the air locks and a seal on the return side shouldbe opened by an apparatus crew; the air-lock doors on the intakeside should be opened and air admitted to reventilate the area insidethe air locks. Brattice-cloth stoppings should be erected in opencrosscuts on the return side to advance fresh air to the last crosscut,which should be left open to provide a return.
The quantity of air admitted through the air lock should be regu-lated so that the return will be kept below the lowest explosive limit
After the newly sealed area has been reventilated to form the nextair lock, fresh-air men should erect a tightly constructed stoppingwith a door in it at a suitable distance outby the one previously built,and erect suitable stoppings to replace the temporary brattice-clothstoppings placed in openings on the return side.
In like manner, with the exception that no seal need be broken onthe intake side, advances should be made by successive blocks untilthe entire area is recovered. As the work progresses, frequentanalyses should be made to determine the composition of fire gaseswithin the sealed area. The oxygen should be kept under controland within safe limits at all times. It is imperative that the oxygenbe kept as low as possible at all times to allow for limited infiltrationof air as the work progresses.
PROCEDURE USED IN UNSEALING HORNING MINE
A section (see fig. 21) of the Horning mine of the Pittsburgh Ter-minal Coal Co., Pennsylvania, was sealed after an explosion that oc-curred during the sealing of a fire on February 3, 1926, and killed20 men. Three bodies had been recovered by rescue crews when asecond explosion occurred, making it extremely dangerous to attemptto recover the other 17 victims. After careful deliberation by thosein charge of the situation, it was decided to seal the affected regionand attempt to recover the bodies by erecting a system of air lockswhen the oxygen content of the sealed area had been reduced to 4percent.
The sealed region is kiiown as the fourth section south and con-sisted of three face entries (Nos. 7, 8, and 9 south) and two buttentries leading from the face entries (known as Nos. 15 and 1.6 buttright entries). The face entries extended approximately 1,000 feetfrom the seals to their faces, and at a point about 500 feet from theseals the two butt entries were turned off from the face entries. Thebutt entries extended about 500 feet from the face entries. Ninerooms, ranging from about 12 to 120 feet in depth, were turned offNo. 15 butt right; no rooms were turned off No. 16 butt. The totaldistance from the seals to the face of the butt entries was about 1,000feet. The fire that caused the explosions was at the face of No. 16butt right, and it was thought that nearly all of the entombed menwould be found on Nos. 15 and 16 butt entries, which proved to becorrect.
Final airloc024.7 Feb.23, 6:00 p.
15R. butt
Motet'and
15 R.
1,100
Loso
1,000
700
300
150
of4 1009,es
tan
Q,
UNSEALING MINE FIRES
PROPOSED SCHEDULE
Step No.1 lt is agreed by all present thatl-ply canvasd stoppingo be erected at point indicated by Net. 1, land 3.
Step No.2 Afterstoppings 1,landlare erected fresh air maybe conducted to the crosscut in which stopping No. lis erected.
Step No.3 Erect match-lumber stoppings where canvasso stoppingu 1, 2.and laxO located, doors to be placed he atoppings
2 and 3, also a pipe in otopping No.2 for the purpose of obtaininggea aamples.
Step No.4 Erect a match-lumber stopping at point indicatedby 4,rea.ve otopping No.3 it break, and erectdonr in originalstopping en rood No. 8.
Step No.5 Erect stopping No. tin rend No.8 at point indi.ated, next erect stopping No.0 on mad No.? as indicated, next
open doors in original stopping en road No.7.Step No.6 Erect 3-ply castas in crosscut at point indicatesi
by the figure?, then proceed to erect a leek euch as that erectedat point No.2 at a point that may be decided upon after exami.'nation nf the ground tss'been made.
Step No.7 The finalair loch tobelocated on roadNo.Oatthe point indicated by the letter A en the mnp.
LegendStoppingo before breaking saale VentilationSteppings to be erected S Location of body
___ Where stoppingo were built Air sampleCanvas brsttice s.'Door
O 3.2 Feb. 32, 12:15 a, st. Ox t,8 Feb. 14. 2:00 a. oc:
--Advanced telopl ne
Not shown on!original map
jot air lockput here
Seal broken Feb. 10,at 2:45 a. re.Air4ock doors now open
Fire8 9 stopping!Original fire 2.3.26
'Recovered Feb. 15, 11:03 p.m.
bu r\\State rebe inspectors on duty
Alex. Mc CandiC.1'. Byrne }S:oos.m.tosooP.m.'S. S, HallRichard Maize } 5:03p.m. to 9:00p.m.
John F BollP.J. Calloghan }:to p.m. to 1:00 n.m.J. J, StokerW. H. Howarth) 3:00a.m. to 9:00a.m.
lohn I Pratt in charge
FIGURE 21.Sketch of procedure of recovery work, 1-Torning mine.
Stopping No. 4, not marked, is represented by the double horizontal line above and tothe left of No, ii.
57
Mon in chargeof ehift
Rescue teams7:OOa. re: ta 3:00 p. re.
j y pyBorrackville, W. Va. Beth. Minen Corp..Johnstown, Pa. Both. Minen Corp..Gallatin. l'a. Pittsburgh Coal Co..Dinomoro, Pa. Bertha Coal Co.
G. S. McCaa(one day)
G. W. Grove(foor days)
5:00p.m. to 11:00p.m.
Indianolo. Pa, Inland Collieries Co.,Mansfield, Pa. Pittsburgh Coal Co..Oakmont, Pa. Mulcan Coal & Coke Co..Coverclale, Pa. Pittsburgh TerminalCool Corp.
G. W. Riggs
11:00p.m. 7:005-nt.
Californio, Pa. Venta Coal Co.,Brawnoctile, Pa. human Ceni di Coke Ce..Orient, Pa, Orient Central Rescue Station.,Ner.:acolio, Pu. Buckeye Coal Co.
58 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
Construction of seals.The permanent brick and tile seals were inNos. 7,8, and 9 face entries and were completed about 8 a. m., February5. A pipe was placed in the stopping on No. 8 face entry to collect airsamples and take water-gage readings. The pipe was equipped withvalves, and one end of it was immersed in a tub of water to releasepressure if desired.
Analysis of atmosphere behind seals 3'/2 hours after sealing.Thefirst air sample was taken from behind the seals at about 11: 30 a. m.,February 5, and gave the following analysis: 2.4 percent of CO2, 13.4percent of 02, 0.8 percent of CO, 11.3 percent of CH4, and 72.1 percentof N2. Additional air samples were taken at about 8-hour intervalsand analyzed by a modified Orsat apparatus on a Bureau of Minesrescue car by chemists from the Pittsburgh Experiment Station ofthe bureau.
Water-gage and barometer readings were taken frequently and aclose check kept on the pressure behind the stoppings. When the pres-sure behind the seals reached 2.25 inches water gage the valve in thestopping on No. 8 face entry was opened and the pressure "bled off"through the pipe placed in the tub to prevent it from increasing. Atno time during the recovery operations did the water gage show thatthe sealed area was under suction. However, on one or two accasionsthe outward pressure was very slight, due to a rising barometer.
Construction of stoppings and air locks.The period necessary forthe oxygen to be reduced was utilized to good advantage in buildrngstoppings for ventilation purposes outby the sealed region, obtainingand placing materials close to the seals and rock-dusting all entriesand crosscuts in proximity to the sealeci territory. During this timean air lock with a line wood brattice was also built outby thestopping on No. 9 face entry.
The air lock constructed on No. 9 face entry and those mentionedlater consisted of two stoppins 15 to 20 feet apart. These wereconstructed of matched white pine and all openings and cracks werefilled with stiff mud. Each stopping had a large 2- by 5-foot dooron hinges, a means of fastening, and a 2- by 2-foot slide door. A linebrattice of matched lumber or brattice cloth was built midway in theentry within the air lock from one stopping to the other. The largedoors of the air lock were used for ingress and egress of rescue crewsand for handling materials; the small doors, when opened, served asthe return from the ninth face entry when ventilation was establishedto the next air lock. By building air locks of this kind, a crew wearingoxygen breathing apparatus could pass through the first door, closethis door, and open the inside door pass through, close the seconddoor also, and carry on their work. òn returning, the inside door wasclosed before the outer one was opened. One door was thus keptclosed at all times, and as far as possible air was prevented fromentering the sealed region from the outside.
All stoppings and air locks were built with white pine 2- by 4-inchframes and uprights, matched lumber, and copper nails. Copperhammers also were used in all construction work. As already men-tioned, cracks and openings in the stoppings were filled with mudto reduce leakage as much as possible.
Analysis of atmosphere behind seaTh 4 days after seaZing.At 6:10p. m. February 9, or about 41/3 days after the permanent seals had been
UNSEALING MINE FIRES 59
erected, analysis of the air was as follows: 4.3 percent of CO2, 4.4percent of 02, 1.1 percent of CO, 36.5 percent of CH4 and 53.7percent of N2. It was then decided that, as by the time ali necessaryarrangements could be made the oxygen probably would be reduced toabout 4 percent, the seals would be broken when the 11 p. m shiftwent underground. Analysis of a sample taken at 10: 50 p. m. gave4.6 percent of CO2, 4.2 percent of 02, 1.5 percent of CO, 36.5 percentof 0114, and 53.2 percent of N2. By the time all of the necessaryarrangements were made and the seal was removed in No. 9 face entryit was 2:45 a. m., and the oxygen was probably reduced to 4 percentor less.
Details of reopeninq sealed srea and recovery of bodíes.Three 8-hour shifts were employed. Each shift included one man in charge,two or three assistants, two State mine inspectors, four rescue teams offive men each wearing oxygen breathing apparatus, and laborers,drivers, and others.
The organization at the fresh-air base consisted of one man incharge, one or more assistants, two State mine inspectors, and therescue crews. Before entering the air lock, each apparatus crew wasgiven detailed instructions on the work the members were to perform.
Whenever one or more apparatus crews were working or exploring,they were backed up with a reserve crew stationed within the air lock.Not more than five permissible flame safety lamps for gas detectionwere allowed underground on each 8-hour shift. Permissible electriccap lamps and flashlights were used exclusively for illumination.
After breaking the seal in No. 9 face entry, a crew wearing appara-tus, supported by another crew in fresh air, passed through the firstair lock and advanced approximately 225 feet in No. 9 face entry. Theconstruction of another air lock was started at this point. When thisair lock was completed, two stoppings were erected in breakthroughsbetween Nos. 8 and 9 face entries. An air sample taken at this timegave 5.2 percent of oxygen between tile two air locks. At the com-pletion of this work the first air lock was opened and a line canvasextended from No. 1 to No. 2 air lock, thereby conducting fresh airto the outer door of No. 2 air lock. Following this, stoppings wereerected on Nos. 7 and 8 face entries by working through No. 2 air lock.When these were completed, an exploration was made between theseals and the newly erected stoppings in Nos. 7 and 8 face entries.These two entries were then ventilated to the new stoppings. One bodywas recovered during this work in No. 8 face entry.
Next, a crew advanced about 250 feet more in No. 9 face entry orjust outby No. 15 butt. An air sample was obtained at this point andthe erection of No. 3 air lock begun. The analysis of this sample gave4 percent of CO2, 3.2 percent of 02, 1.4 percent of CO, 46.6 percent ofCH4, and 44.8 percent of N2.
On completion of the air lock, two stoppings were again erected be-tween Nos. 8 and 9 face entries, and a line brattice was extended andair conducted from No. 2 to No. 3 air lock. From this air lock stop-pings were erected in Nos. 7 and 8 face entries and No. 16 butt entryand an air lock in No. 15 butt between Nos. i and 2 rooms. One bodywas recovered in a breakthrough between Nos. 15 and 16 butts duringthis operation,
60 PROCEDURE JN SEALING AND UNSEALING MINE FIRES
The oniy difficulty encountered in the erection of stoppings was inconnection with the two constructed at this point in Nos. 7 and 8 faceentries. A trip of cars and a motor were found in No. 8 face entry.The cars were wrecked and jammed in the entry at the place wherethe plan of procedure indicated the stoppings were to be rected. Itbecame necessary to change the location of these two stoppings fromthe original plan and to erect them approximately 50 feet inby. Beforethe stoppings were erected it was necessary to cut one of the wreckedcars to permit the apparatus men to work around the wrecked tripin safety.
After the face entries and No. 16 butt were ventilated to the newlyerected stoppings and No. 15 butt to the air lock, a crew was sent onan exploration trip into Nos. 15 and 16 butt entries and found thebodies of 14 men, which left one body still to be found. All of thebodies except the one that had not been located were recovered andpassed through the air lock by 5 a. m., February 14. Analysis of anair sample taken inby the last breakthrough in No. 16 butt at 2 a. m.,when search for bodies was being made, showed 3.1 percent of 002, 5.6percent of 02, 0.9 percent of co, 45.6 percent of CH4, and 44.8 percéntof N2.
After Nos. 7, 8, and 9 face entries were explored and ventilated totheir faces, and Nos. 15 and 16 butts were again explored to locatethe remaining body, it was finally found and recovered the followingnight (11 : 03 p. in.) from under a fall of slate at the face of No. 6room off No. 15 butt. After the last body was recovered on February15, permanent seals of concrete blocks with tile centers were erectedoutby the air lock in No. 15 butt and the stopping in No. 16 butt. Thisregion was left sealed until March 13, when it was unsealed andreventilated.
Final unsealing of Horning fire region.When unsealing the finalarea of the Horning mine in which the fire had been, a base of opera-tions was established outby the seal in No. 15 butt, and all necessarymaterials and equipment required for the unsealing were placed atthe fresh-air base. Three rescue crews were employed for this work.Nos. i and 2 crews, respectively, with No. 3 crew in reserve, brokethe intake seal and entered the air lock, which had been erected andused during the recovery of the bodies. No. i crew advanced to theface of No. 16 butt, tested for carbon monoxide with a detector, andplaced a maximum and minimum thermometer at what was consid-ered to be the hottest place. No. 2 crew placed a maximum and mini-mum thermometer in the first brèakthrough inby the seal on No. 15butt and advanced to between rooms 8 and 9 in No. 15 butt. Allcrews then returned to the outside of the air lock and reported. No.i crew reported that the maximum and minimum thermometersplaced at the face of No. 16 butt and in the first breakthrough insidethe air lock read the same and that there was no indication of carbonmonoxide or heat.
To check these observations, a second exploration trip was made.No. 2 crew went to the face of No. 16 butt and No. 3 crew to betweenrooms 8 and 9 in No. 15 butt. No. i crew acted as reserve. Similarobservations and reports were made. A sample taken at the seal ofNo. 16 butt on March 11 showed 2.9 percent of CO2, 0.1 percent of02, 0.1 percent of CO, 88.8 percent of CH4, and 8.1 percent of
IJNSEALING MINE FIRES 61
N2, and with this favorable analysis it was decided to reventilate thearea. A line brattice was extended through the crosscut outby theseals in Nos. 15 and 16 butts, and the seal in No. 16 butt was openedby a rescue crew. The doors in the air locks in No. 15 butt were thenopened and the fire gases removed as quickly as possible. The rescuecrews then entered the area and removed the standing fire gases inthe rooms off No. 15 butt.
Outstanding factors in successful unsealing of Horning fire area.-Twelve crews of five men each, wearing oxygen breathing apparatus,built all air locks and stoppings used in recovering the bodies. Inaddition they made exploration trips and carried all bodies to thefresh-air base. Three crews were used later in unsealing the finalblock on March 13, 1926. No long trips were attempted at any time;300 to 400 feet was the maximum distance the crews traveled orworked ahead of fresh air. All of the crews engaged in the opera-tion did exceptionally good work, and too much can not be said fortheir training, obedience, willingness, endurance, and courage. Theentire project was carried on without injury to anyone and with butlittle apparatus difficulty. This can be attributed largely to a well-planned well-organized, and well-conducted procedure drawn upbefore th work was started and followed by strict adherence to theplan at outlined. The air sampling and analysis, which showed thecondition behind the stoppings at all times, were important factors inthe successful conclusion of the work. The experienced men com-posing the apparatus crews and the men in charge of the differentshifts also aided materially in successfully completing the task.
Air locks were employed, also, to unseal mine fires at the Sunnysidemine of the Utah Fuel Co., Sunnyside, Utah, in 1920; the Rockwoodmine of the Roane Coal & Iron Co., Iockwood, Tenu., in 1925; theConrielisville No. 1 mille of the Connelisville By-Product Coal Co.,Pursglove, W. Va., in 1927; and the Woodward mine of the GlenAlden Coal Co., Edwardsville, Pa., in 1927.
RECOVERING A SEALED AREA BY RE VENTILATION
When a decision has been made to recover a sealed region by directventilation, an air lock should be constructed, )referably near theintake seal. A rescue crew using a life line and fully equipped forthe work at hand should break the seal, enter, observe conditions,take temperature readings and air samples, and return to the fresh-airbase. If the observations and examination of the affected regionhave shown that conditions are favorable, the return seal should bebroken by an apparatus crew; the air lock should then be opened toadmit air. The area should be ventilated, but the combustible gasesin the main return, if feasible, should be kept below the lowest ex-plosive limit. The unsealing of the final fire area of the Horningmine on March 13, 1926, is a good example of unsealing by directventilation.
If an explosion is expected, it is advisable that all men be outof the mine before the air is actually directed into the sealed area.Some automatic arrangement should be employed to allow ample timefor all persons to reach the surface before the fire gases are actuallymoved. A reasonable period should be allowed for the gases to be
62 PROCEDtJRE IN SEALING AND NALIN MINE rnE
removed, and frequent samplings should be made of the return airfrom the mine; the time for any person to enter should be governedby the quality of the return air. This may be tested by installing acontinuous methane recorder in the main return from the mine or bysystematic periodic sampling and analyzing. If the workings underseal are extensive, it probably will be advisable for crews equippedwith oxygen breathing apparatus or possibly with gas masks to re-enter the mine and completely clear any standing fire gases out of thefire area.
RECOVERY PROCEDURE FOLLOWING MINE EXPLOSIONS
An efficient organization, proper and adequate equipment and ma-terials, and proper procedure are of prime importance in conductingrescue and recovery operations safely after a mine explosion. Im-proper procedure may sacrifice possible chance of rescuing personsleft alive in a mine after an explosion and may also result in lossof life of men engaged in recovery work. As soon as possible thefan should be inspected and kept running with an attendant incharge; electric current should be cut off from the mine; mine en-i rances guarded and roped off; and a checking in and out systemestablished Rescue and recovery crews, with other personnel andnecessary equipment and material, should be assembled promptly asindicated in previous discussion of organization, equipment, andmaterials.
EXAMINATION OP MINE OPENINGS
Before exploring is begun, a preliminary examination should bemade of all openings and escapeways, as men overcome by afterdampmay be found near openings.
If the explosion has occurred in a shaft mine and the cage, signal-ing devices, and headframe have been damaged or destroyed, thesafest and most convenient shaft compartment should be used fordescent. It may be necessary to use a bucket for descending theshaft to make a preliminary examination around the shaft bottom;however, a cage should be made available if at all feasible, as littleprogress can be made with a bucket, except possible in the earlystages of the investigation preparatory to doing effective recoverywork.
ESTABLISHING VENTILATION
If the ventilating fan has not been destroyed or damaged so itcannot be operated, it should be kept running; with the fan runningnormally, ventilation will be established only to the point wherestoppings have been destroyed by the force of the explosion. Theventilating current should not be reversed without good reason andthen only on written orders to those in charge; this is of vital im-portance, particularly if any live men are known to be in the mine.If it is impossible to operate the fan, repairs or replacements shouldbe made immediately as little or no recovery progress can be madewithout adequate vèntilation. Advantage should be taken of anynatural ventilation that may be established to make a preliminaryexamination of the region of mine openings and for a short distanceinde the mine.
RECOVERY PROCEDURE FOLLOWING MINE EXPLOSIONS 63
ENTERING MINE AND ESTABLISHING FRESH-AIR BASE
When the necessary organization lias been formed, equipment andmaterials assembled, and ventilation established, exploration of themine should be started.
The officials in charge of the shift should check the crews goingunderground (fig. 22) to see that everyone is properly equipped
foi' the work at hand and that only persoiis whose services may be ofdefinite use are allowed to go into the mine.
On entering the mine, the rescue and recovery crews should ad-vance in fresh air to the point where ventilation has been destroyedand establish a fresh-air base outby that point.
64 PROCEDImE IN SEALING AND UNSEALING MINE FIRES
ESTABLISIUNG TELEPHONE COMMUNICATION
Portable telephones may be used to advantage to keep in touchwith outside when crews are advancing. However, a standard-typetelephone (preferably permissible type, if available) connected withthe outside should be installed at the fresh-air base, with an operatoralways present. As recovery work progresses, the telephone systemshould be extended and additional telephones installed so that atelephone will always be in reasonable proximity to the advancecrews, though ordinary-type telephones should not be installed orleft where they are likely to come in contact with explosive gas.
DUTIES OP RESCUE AND RECOVERY CREWS
Owing to the different nature of their duties and requirements,underground crews often are designated more or less indiscriminatelyas rescue crews and recovery crews. Rescue crews comprise menequipped with gas masks or oxygen breathing apparatus and espe-cially trained and equipped to make explorations, perform work inirrespirable air, and, when the occasion arises, to rescue living men.Recovery crews are composed of bratt.ice men, men for handling andtransporting material and bodies, drivers, telephone attendants, tim-bermen, trackmen, road cleaners, and other miscellaneous personnel.
Rescue crews work in close cooperation with recovery crews bymaking explorations ahead of fresh air to reach live men, locatebodies, test the mine air, look for fires, and erect stoppings whererespiratory protection is required. Men wearing heavy breathingapparatus should not transport bodies except in an emergency, andthen oniy for short distances; those who have not worn oxygenbreathing apparatus are prone to ask apparatus men to perform du-ties that should not be required of those who do this very arduousand hazardous work.
Men iii charge of the shifts, the fresh-air base, or other officials andmembers of rescue crews should guard against unnecessary breathingof afterdamp to prevent impairment of their usefulness and judg-ment. Members of recovery crews not equipped with adequate re-spiratory protection should not be permitted to go ahead of freshair, as they may be overcome or their efficiency reduced by breathingthe harmful gases likely to be encountered in mine rescue andrecovery work.
EXPLORATIONS AHEAD OP FRESH AIR
After a fresh-air base has been established, exploring should bedone ahead of fresh air by rescue crews wearing oxygen breathingapparatus or possibly gas masks if it is known that the masks may beused safely to look for live men and fires, locate bodies, and observeconditions. It is always advisable to make short trips ahead of freshair (about 250 to 400 feet), as experience has shown that more canbe accomplished and the work carried on more safely by this methodthan by long and dangerous trips far in advance of fresh air. Longexploration trips should not be made unless they are absolutely nec-essary to save life or to do other work positively required for thecontinuance of recovery operations. Exploration trips ahead of freshair may be performed largely by gas-mask crews if it is fairly defi-
RECOVERY PROCEDURE FOLLOWING MINE EXPLOSIONS 65
nitely known that masks can be used safely. Oxygen breathing-apparatus crews should be held in reserve to support gas-mask crewsor for use where gas masks cannot be worn with safety. When gas-mask or oxygen breathing-apparatus crews are working ahead offresh air, another oxygen breathing-apparatus crew, fully equipped
with apparatus adequately charged and in good condition, alwaysshould be held in reserve at the fresh-air base (fig. 23).
Before starting an exploration ahead of fresh air, the crew shouldexamine carefully their apparatus, life line, and other equipment toinsure that everything is in good condition; they should be given
66 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
definite instructions by the man in charge of the fresh-air base asto the extent of the trip, distance to travel, things to observe, andtime to be taken in making the trip.
On leaving the fresh-air base the rescue crew should travel a shortdistance, probably 50 to 100 feet, ahead of fresh air and stop longenough to make sure that their apparatus are airtight and func-tioning properly. Then, carrying a life line or batteryless-typeportable telephone and wire for giving signals, they should proceedslowly, in single file, about 6 feet apart. They should examine theroof and roadway; mark with chalk the direction of travel, witharrows pointing to the fresh-air base; mark the name or initials ofthe crew captain or name of the crew, and the day, month, and yearon the faces of all rooms, entries, etc., and at the farthest point ofthe trip; and carefully note conditions and report their observationsto the man in charge when they return to the fresh-air base.
During exploration trips ahead of fresh air, rescue crews shouldact in accordance with previous instructions and training, havingregard at all times for their own personal safety. Good judgmentand common sense are required to conduct exploratory work aheadof fresh air safely and efficiently.
RESTOIUNG VENTILATION
Ventilation must be restored throughout the mine for the recoveryof all men and bodies and for the removal of afterdamp.
If no fires are found after exploring ahead of fresh air for somedistance, possibly through several breakthroughs or crosscuts, toascertain conditions, the next step is to erect the necessary stoppingsto ventilate the explored region.
CONSTRUCTIONS OF STOPPINGS
If an explosion has affected a large area, many temporary stoppingswill be required to restore ventilation. Temporary stoppings shouldbe made as nearly airtight as possible and strong enough to withstandthe pressure that will be required to carry air to the face regions.Such material as may be available should be used to construct tem-porary stoppings. Brattice cloth or canvas of good grade has num-erous advantages (fig. 24), but burlap, muslin, and bed ticking maybe used until better material is available.
Temporary stoppings near mine openings or other places wherethey will be subjected to considerable air pressure should be con-structed of two to four plies of brattice cloth, depending on the sizeof the stopping and the distance air must be carried. Temporarystoppings should be set far enough (at least 4 to 6 feet) inside ofcrosscuts or other openings to leave space for the later constructionof stronger and tighter stoppings.
As soon as possible, semipermanent stoppings of boards or strongermaterial, or permanent stoppings of bricks, cement blocks, tile, etc.,should be erected to replace temporary stoppings, particularly wherethe temporary stoppings are under considerable air pressure.
Details of the construction of temporary and permanent stop-plugs are described in the section on sealing mine fires.
As recovery work progresses, a large number of temporary stoppingsmay be in use, and to insüre that these are kept tight and in good
tinued until the entire region affected by the explosion has beenrecovered.
in ventilating any portion of a mine after an explosion, the after-damp should be conducted to the outside by the most direct route.
RECOVERY PROCEDURE FOLLOWING MINE EXPLOSIONS 67
condition, men should be appointed on each shift to patrol andkeep the temporary stopprngs as nearly airtight as possible.
CONTROL OF VENTILATION
The procedure of alternately exploring ahead of fresh air andadvancing the air by erecting temporary stoppings should be con-
68 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
Permitting the poisonous gases to travel through other sections ofa mine may seriously endanger the lives of survivors of the explosionor persons enpged in the rescue or recovery work.
Safe practice requires that currents of air be conducted so theventilation will always be under the control of the man in chargeof the shift and the paths the air is traveling will always be knowndefinitely; it is extremely dangerous after an explosion, especiallyin a gassy mine, to permit air to travel over or through unexploredportions of the mine. Unless this vital precaution is taken, anexplosive mixture of gas may be brought in contact with a fire,thereby causing another explosion, possibly with disastrous effects;this has occurred in several cases.
All sections, entries, rooms, and other open accessible workings,etc., if possible should be cleared of afterdamp as work advances;if this is not done, fires may be bratticed off and reach a serious stagebefore discovery; or explosive, asphyxiating, or poisonous gases mayseep from bratticed-off areas, enter the ventilating current outby thepoint where recovery work is in progress, and seriously affect mem-bers of the rescue or recovery crews or possibly cause an explosion.
Line brattice will be, required for ventilating faces of entries androoms or when it is necessary to split the air current in entries. Ifa brattice is required for a considerable distance, it should be erectedby setting posts about 8 to 12 feet apart in the center or on one sideof the passageway; a board should be nailed along the top of theposts and the top of the brattice cloth nailed to it; probably the bot-tom end of the brattice cloth also should be nailed to a board or itcan be held in place by lumps of coal, pieces of slate, etc.
When a short-line brattice is required to clean out the face df aworking place, as from the last crosscut to the face of the place,sometimes especially in low workings or workings of medium height,it can be erected quickly by having a number of men hold the brat-tice cloth in place instead of fastening it on posts. A roll of brat-tice cloth long enough to reach the desired distance should be heldupright in the passageway where the outby end of the line bratticeis to start; several feet of the cloth should then be unrolled and heldby one of the men, while others advance toward the face unrollingthe cloth and holding the unrolled portion to the roof as the rollis advanced, until the ventilating current reaches and clears the faceof afterdamp. After the face has been ventilated the cloth can bedropped2 rolled up, and used again. Where it can be used, thismethod is preferable to setting posts and nailing the brattice cloth,as it is much quicker.
EXAMINING POR AND EXTINGUISHING PIRES
Frequently smoldering fires (which may be dormant for as longas several days and fanned to life by the entrance of fresh air), andsometimes active fires are found after mine explosions. Doors, tim-bers, gob, dust, brattice cloth, and coal are likely to be set on fireby the heat and flame of the explosion. Such fires are extremelydangerous in gassy mines, as they may ignite an explosive mixtureof gas. When exploring ahead of fresh air, rescue crews shouldmake careful examination for fires; and as ventilation is advanced,
RECOVERY PROCEDURE FOLLOWING MINE EXPLOSIONS 69
frequent inspections should be made of the return-air currents foi'smoke or heated air.
If fires are found while rescue crews are exploring ahead of freshair, they should be extinguished if possible with water, rock dust, orfire extinguishers before the fresh air is advanced to the fire. Whenthe fire is of such proportions or is so inaccessible that it cannot beextinguished, it should be seaTed promptly and effectively.
If smoke and an explosive mixture of gas are encountered and thelocation of the fire is unknown, it is advisable to seal the region con-taining the fire, or the entire mine, at once. When the latter is done,
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to continue recovery operations it may be necessary to use air locksto work around the fire area, as was done following an explosion inFederal No. 3 mine of the New England Fuel & Transportation Co.,Everettville, W. Va., in May 1927.
In this instance, smoke and an explosive mixture of gas were encoun-tered shortly after recovery work was started, and the safety of themen engaged in the work demanded that the entire mine be sealeduntil further plans could be made. It was decided to continue recov-ery operations by air-locking around the area containing the fire.Figure 25 shows a section of this mine and gives a comprehensive ideaof how the work was conducted. Undoubtedly, it was the largestair-locking job ever attempted in a bituminous mine; approxii.ately
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70 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
35 oxygen breathing-apparatus crews, working in 6-hour shifts, wereemployed for a week, and 14 air locks and about 50 stoppings wererequired to work around the region containing the fire. Details re-garding the construction of air locks and procedure to follow have beenexplained previously in the discussion on the recovery of bodies andunsealing the fire following an explosion in the horning mine; andthe procedure for sealing a fire is described in the section dealing withthat subject.
RESCUE AND REMOVAL OP LIVE MEN
Sometimes live men are found after an explosion. Usually they aresuffering from poisonous or asphyxiating gases, burns, or injuries.Men found affected or overcome in an atmosphere containing after-damp should have an oxygen breathing apparatus (preferably a half-hour type) placed on them and should he carried to fresh air as soonas possible. If sufficient oxygen is present to support life (a lightedflame safety lamp will indicate this), a gas mask or self-rescuer prob-ably can be used safely instead of an oxygen breathing apparatus.
As soon as possible after live men are brought to fresh air, theyshould be given oxygen to breathe. The oxygen should be admin-istered (preferably by means of an inhaler for at least 30 minutesto remove carbon monoxide from the victim s blood. If rescued menare breathing slowly, or not at all, but show indications of life, arti-ficial respiration should be administered in conjunction with oxygenuntil they are revived or until it is known definitely that it will beimpossible to revive them.
Occasionally, live men are found behind barricades erected to pro-tect themselves from afterdamp. Great care should be exercised, ifthe region immediately outside the, barricade is in an irrespirableatmosphere, to prevent poisonous or noxious gases from entering thebarricade while men are being rescued. If fresh air can be advancedto the barricade in a short time, this is desirable and should be donebefore the barricade is opened. If it is impossible to conduct freshair to the barricade in a reasonably short time, provision should bemade to admit the least possible amount of irrespirable air behindthe barricade when it is opened by erecting a tight canvas stopping,with a small opening covered with canvas, a short distance (about 10to 15 feet) outby the barricade to allow sufficient room to set astretcher lengthwise between the stopping and barricade.
After the stopping has been erected, an opening large enough toadmit an open stretcher should be made in the barricade and coveredimmediately with canvas. After these arrangements have been com-pleted, the following procedure should he used in rescuing men frombehind the barricade.
If all or some of the men found behind barricades can walk, theyshould be provided with the necessary protective equipment, such asan oxygen breathing apparatus (preferably half-hour type), or, if aflame safety lamp will burn outside the barricade, a gas mask or self-rescuer, and led or assisted to fresh air. If they are unable to walk,four men with a stretcher should pass through the stopping, admit-ting as little air as possible, and enter the space between the stoppingand barricade. They should then pass through the barricade againadmitting the least possible amount of air, and enter the space behind
RECOVERY PROCEDURE FOLLOWING MINE EXPLOSIONS 71
the barricade. A man (depending on the condition of the men behindthe barricade) should be selected for rescue, provided with the neces-sary protective equipment, loaded on a stretcher, taken through theopening in the barricade (the opening then being tightly closed),then through the stopping (this opening then being tightly closed),and finally carried to fresh air by the shortest and quickest route.These operations should be repeated until all of the men behind thebarricade have been rescued. Every effort should be made to pre-vent the admission of irrespirable air through either the stoppingor barricade while men are entering or leaving. If reasonable careis exercised, several men can be rescued from behind a barricade withthe admission of only a small amount of the harmful air into thebarricaded space.
All rescued men, whether from behind barricades or otherwise, onreaching fresh air should be given first-aid treatment, consisting ofartificial respiration, if required, adniinistration of oxygen, treat-ment for shock, and dressing of wounds, burns, or other injuries.Rescued men should be well covered and wrapped with blankets orquilts before being taken outside, and those unable to walk should beplaced on stretchers and carried or hauled to the outside. Allrescued men should be taken to an emergency or permanent hospitalfor further observation and treatment.
HANDLING BODIES
After an explosion, dead bodies may be found in various parts ofthe mine. Some bodies may have no injuries or mutilations, whileothers may be badly damaged, dismembered, or decomposed.
All bodies should be wrapped in brattice cloth or canvas by therecovery crews and transported to the morgue. When bodies arenot recovered for several days they should be sprayed well with adisinfectant, such as a strong solution of creolin or lysol, before be-ing touched, handled, or wrapped. A tag bearing the serial numberand the location where the body was found should be attached toeach body. If the location has not been marked previously on theroof or rib, this should be done by the recovery crew. The location,position of the body, and check number or name also should bemarked on the mine map. Nothing should be removed from a bodywhile it is in the mine, except in the presence of witnesses, and thenonly if a written record is made of the material removed. Any ma-terial removed from a body should be given to a responsible personto be turned over to the man in charge of the morgue or to relativesof the victim. Bodies received at the morgue should have a morguenumber assigned and should be identified if possible.
The official in charge of the morgue should make a record of tagEattached by the recovery crews and the check number, if checks arefound on the body, and a record of clothing, shoes or boots, money,watch, or other jewelry found on the body; a description of the fea-tures, color of hair and eyes, height, weight, and teeth, old scars orfractures, and probable age of the victim.
All clothing and other articles removed from a body should bewrapped in cloth or canvas, tied securely with a tag inside and themorgue number outside, and delivered to the coroner or the relativesof the deceased.
72 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
SETTING TIMBERS
Many timbers may be knocked out by the force of the explosionand the roof may be weakened by the heat. As a protection to rescueand recovery crews and others who are required to travel roadways,manways, and entries, timber crews should remove dangerous roofand set necessary timbers as soon as possible.
CLEARING ROADWAYS
Roadways should be cleared of falls and debris and necessary re-pairs made to the haulage tracks as soon as possible after an ex-plosion. The transportation of material and bodies and the recoverywork in general will be facilitated greatly if the haulage tracks andhaulage equipment are made available for use. Storage-battery loco-motives (permissible type), horses, or mules should be provided formotive power. Trolley-pole or cable-reel locomotives should not lieused because of the hazaçds of igniting explosive gas.
PREPARATION FOR RESUMING OPERATIONS
After the area affected by a mine explosion has been explored, thebodies removed, fires (if any) extinguished or sealed, and the in-spectors and mine officials have completed their investigations, crewsshould be set to work building permanent stoppings, cleaning haul-age roads and air courses, and making such other repairs as may benecessary ti safe operation of the mine.
When all necessary repairs and changes have been made, the Statemine inspector should examine the mine before regular work isstarted and if in his judgment the mine is in safe condition, opera-tions may be resumed.
RESCUE AND RECOVERY OPERATIONS COURSE
Since 1925 the Bureau of Minés has conducted a course of instruc-tion in rescue and recovery operations (commonly called advancedmine rescue training) for mine officials, State mine inspectors, andmembers of oxygen breathing-apparatus crews, based on informationcontained in Miners' Circulars 33, 34,35, and this publication (Miners'Circular 36). About 3 days are spent on the surface (fig. 26) dis-cussing mine gases and describing, using, and testing the equipmentand devices employed in rescue and recovery work. About 2 daysare spent in underground work in training class members in methodsof actual recovery. A hypothetical fire or explosion is assumed tohave occurred in a section of a mine involving at least a pair ofentries and several rooms.
The instructor should visit the area to be in the practice recoveryoperations before the underground work is started, and shouldarrange the details of the problem by marking with chalk or byplacing signs, such as "methane", "carbon monoxide", "depletedatmosphere", "fire", "barricaded men", "dead men", "falls", etc., atsuitable places. When an explosion is involved in the problem,stoppings, doors, and overcasts should be marked as "blown out"to show that ventilation has been destroyed; various other indicationsof force and violence also should be indicated. Figure 27 gives a
FIG
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After surface conditions have been determined, the crews shouldproceed underground to the point where it is assumed the fresh-air
RESCUE AND RECOVERY OPERATIONS COURSE 75
comprehensive idea of how to arrange a section of a mine for atypical problem.
Many different problems may be devised, depending on the nat-ural and assumed conditions and the arrangement of problem.
PROCEDURE BEFORE GOING UNDERGROUND
On the day before starting the underground problem, the mineofficials and oxygen breathing-apparatus and gas-mask crews, com-posing the class in rescue and recovery operations, should be noti-fled to report at a predetermined place at a specified time. In someinstances, companies having a rather large organization or a minerescue organization composed of several companies arrange a prob-lem without previously informing the men who are to take partin the recovery work; the crews and other personnel are notified(usually early in the morning) as though an actual mine fire orexplosion had occurred; this method, used occasionally, gives anidea of the time required to assemble officials and crews and to forma temporary organization in an actual emergency. The class mem-bers should form crews and assemble and test oxygen breathingapparatus, gas masks, gas-detecting devices, and other equipment andmaterials required for the underground work.
SURFACE ARRANGEMENTS
Before going underground, after an assumed or actual mine fireor explosion, officials arid crews should obtain information on surfaceconditions and make necessary arrangements to insure their ownsafety, about as follows:
Power should be cut off all electric lines leading underground.It should be ascertained that the fan is in operation.A man should be stationed at the fan to see that it continues to
run and to keep unauthorized persons away from it.A checking in and out system should be established.All mine entrances should be roped off and guarded.Everyone who goes underground should be searched for smokers
articles, matches, and pocket lighters, and iio one except authorizedpersons should be allowed to go underground.
Permissible electric cap lamps, flashlights, and flame safetylamps only should be permitted underground.
AlI flame safety lamps should be examined and tested carefullybefore being taken underground.
A minimum number of flame safety lamps should be used.A map of the mine, showing openings, development, and other
important features, should be obtained.Information should be obtained from the mine superintendent
and other mine officials regarding underground cònditions.Personnel, equipment, and material should be checked carefully
to ascertain that everything required is at hand.
PROCEDURE AFTER GOING UNDERGROUND
76 PROCEDURE IN SEALING AND UNSEALING MINE FIRES
base is to be established, and all information obtained on the sectionof the mine in which the explosion is assumed to have occurred shouldbe reviewed.
The oxygen breathing-apparatus and gas-mask crews are assignedtheir duties; one crew is designated to explore ahead of fresh airto a predetermined point, and another is selected to act as reservecrew. After the crew captains have received their instructions, theyshould discuss their various duties, arrange their crews accordingly,and the captains of the crew about to explore and of the reserve crewshould examine the apparatus of their crew members. After dis-cussing details with his crew, the captain of the exploration crewshould report to the man in charge of the fresh-air base that he Isready to proceed. Before the crew leaves, the instructor or man incharge of the fresh-air base should give the captain definite instruc-tions as to the objecte of the trip, observations the crew is to make,distance it is to travel, and the extent of the exploration. In addi-tion, there should be a definite understanding with the crew captainas to the time of return of the crew to the fresh-air base.
FIRST EXPLORATJON
After the captain has checked the apparatus of his crew and hasliad his own apparatus examined by one of the crew members tomake sure each apparatus has sufficient oxygen and is properly ad-justed, the crew should advance a short distance ahead of fresh air.stop long enough to ascertain that all apparatus are air-tight andfunctioning properly, and then proceed on the trip. The exploringcrew should carry such equipment as a flame safety lamp, carbonmonoxide detector or canary, chalk, writing pads and pencils, ap-paratus wrenches, and screw drivers. Crew members should use alife line or batteryless-type Portable telephone and cable, proceedslowly in single file about 6 feet apart, and not become separatedwhile making the exploration. They should examine the roof androadway; mark with chalk the direction of travel, with arrows point-ing to the fresh-air base; write the name or initials of the captain orname of the crew and the day, month, arid year of the exploration onthe face of rooms, entries, and at the farthest point of the trip;carefully observe conditions; and return and report their observa-tions to the man in charge at the fresh-air base.
ADvANCING FRESH AIR
After the first exploration has been completed, observations madeby the exploring crew are discussed by the man in charge of the fresh-air base, crew captains, and team members. If subsequent explora-tions are indicated before fresh air is advanced, they are made by adifferent crew in the same manner as the first exploration. 'Whenit is found advisable to restore ventilation by advancing fresh air,one of the crews, preferably the reserve crew, or a gas-mask crew,proceeds to erect temporary stoppings and perform such other workas may be required to advance the fresh air to a predetermined point,after which the fresh-air base is moved to this point.
The above procedure of exploring ahead of fresh air and advancingfresh air is continued by steps until the entire region known or as-
Mine Rescue Standards: Tech. Paper 334, Bureau of Mines, 1923, 44 pp.
RECOMMENDED EtJLES 0F PROCEDURE 77
sumed to have been affected by the fire or explosion has been re-covered. The solution of adverse conditions encountered in workingthe problem, such as accumulations of methane, concentrations ofcarbon monoxide, oxygen-depleted atmospheres, fires, barricades, etc.,should be left largely to the crew captains, team members, and otherstaking the training, the instructor only seeing that, proper procedureis followed.
It should be remembered always that certain safety precautionsmust be impressed on the crews and others undergoing training toprepare them as far as possible to handle and perform actual rescueand recovery work.
RECOMMENDED RULES OP PROCEDURE
It should be emphasized that haphazard methods of procedure dur-ing rescue and recovery operations after mine fires and explosionshave proven costly in both life and property. Proper procedure andan efficient organization, with proper and adequate equipment andmaterials are vital in conducting rescue and recovery work safely.
The following important rules of procedure are recommended forboth assumed and actual rescue and recovery operations:
After the fan has been repaired and put in operation (if out ofcommission), or if the fan has not been damaged, a fresh-air baseshould be established underground and telephone communication es-tablished to the outside. Portable army-type telephones may be usedfor this purpose; however, standard mine telephones (preferably per-missible type) are desirable. As work progresses and the fresh-airbase is advanced, the telephone system should be extended so thattelephone communication will always be available between the fresh-air base and the outside.
The followirg is recommended for transmitting, receiving, andstandardizing signals from an exploring crew to the fresh-air baseand from the fresh-air base to the crew:
Life line consisting of about 1,000 feet of sash cord wound ona metal reel. Although this means of transmitting signals has beenused widely, however, it is far from satisfactory, as it is extremelydifficult to transmit signals clearly when the exploring crew is severalhundred feet away from the fresh-air base.
Life-line signals that are used generally and for the purpose ofstandardization should be as follows:
1 puli, "stop" if traveling or "all right" if at rest.2 pulls, "advance."3 pulls, "retreat" (from fresh-air base to team, "return at
once").4 pulls, "distress."
Horn or other audible signals between crew members to be thesame.
The crew will keep tile life line stretched or taut at all times to beable to give or receive signals.
78 PROCEDIIRE IN SEALING AND IINSEALING MINE FIRES
As the crew retreats toward the fresh-air base, the life line shouldbe rewound on the reel.
(e) Portable telephones (batteryless type) are more efficient andsatisfactory than the commonly used life line. When such telephonesare being used, conversation between the crew captain and the fresh-air base should be limited to the absolute minimum necessary tocarry on the work, as the crew captain is greatly handicapped in pro-nouncing words by the mouthpiece of the oxygen breathing appa-ratus, particularly those requiring use of the lips. Moreover, unlessthe crew captain has had considerable experience he may be inclinedto talk unnecessarily and if not careful may cause leakage around hismouthpiece. Efforts at conversation by the crew captain should beconfined largely, if not entirely, to the transmittal of signals ofabout the same extent as with a life line. The man at the fresh-airbase may talk fairly freely to the crew captain, but not enough toconfuse the latter in his work; the use of extended conversation islikely to slow up or handicap the work of the rescue crew.
The telephone cable should be rewound on the reel as the crewretreats toward the fresh-air base.
3. Before leaving the fresh-air base for exploration ahead of freshair, the captain of an oxygen breathing-apparatus crew should dothe following:
Examine the apparatus of each crew member to see that it isproperly adjusted and that the oxygen is turned on.
Have a definite understanding with the man in charge of thefresh-air base as to the purpose of the trip, distance to travel, extentof the exploration, and time the crew is to return to the fresh-airbase.
(o) Make sure that a reserve crew, with apparatus in good condi-tion and an adequate supply of oxygen, is at the fresh-air base.
(d) Read the gage in each apparatus to determine that each mem-ber of his crew has an adequate supply of oxygen for the contem-plated trip.
4. The minimum amount of oxygen for each apparatus, when anexploration is to be made ahead of fresh air, should be as follows:
Two-hour-type apparatus only is recommended for, explora-tions or other work ahead of fresh air in mines.
Generally, it is inadvisable to start an extensive explorationwith less than 11/2 to 2 hours' supply of oxygen in each apparatus.
(e) Obviously, it should be possible to complete any contemplatedexploration trip and have at least 30 minutes' oxygen supply remain-ing in each apparatus when the crew returns to the fresh-air base.
(d) Explorations ahead of fresh air with oxygen breathing appa-ratus should never be attempted with less than 30 minutes' oxygensupply in each apparatus, except possibly in an effort to save life.However, even if life is involved, it should be reasonably certainthat a sufficient supply of oxygen is available to permit the wearerof the apparatus to perform the required work and return to thefresh-air base before the oxygen supply is exhausted.
5. When exploring ahead of fresh air, crews should mark theircourse of travel, location of bodies7 faces of rooms and entries, andthe farthest point of the exploration. They also should carefullyobserve conditions and report to the man in charge on returning tothe fresh-air base.
RECOMMENDED RULES OF PROCEDURE 79
6. Exploration trips in coal mines should not be taken under thefollowing conditions:
In dense smoke, except with life line or portable telephones,and then only to save life or to turn valves or open or shut doorsessential to recovery operations. Such trips should not extend longerthan a few hundred feet, even when the route is fairly free ofobstacles.
When an explosion from gas is probable.(e) When it is necessary to crawl on hands and knees because of
low roof, slate falls, or other obstructions.When it is necessary to wade in water more than knee deep.In dangerously high temperature with high humidity.With less than a full crew of five men.With apparatus not adequately charged or in unsafe condition.Unless there is a reserve crew, fully equipped, at fresh-air
base, except for very short trips.7. 'Where possible, it is always advisable to make short trips (say,
four or five breakthroughs) ahead of fresh air rather than long anddangerous explorations. Experience has shown that more can beaccomplished and the work carried on more safely by this methodthan by trips far in advance of fresh air.
8. With a crew in proper physical condition and a reserve crewwearing apparatus at the fresh-air base, explorations in flat coal bedsnot to exceed 1,000 feet (2,000 feet per round trip) may be made inirrespirable gases if necessary, provided conditions are favorable.By favorable conditions are meant a nearly level unobstructed course,height 5 feet or more, good roof, and air clear or so nearly clear thatvision of the crew is not materially obscured.
9. For pitching bedsthat is, any beds that dip or rise more than1 foot in 19 feetthe maximum distance of 1,000 feet recommended forflat beds should be reduced proportionally as the pitch increases. Ex-plorations in advance of fresh air should never be undertaken onpitches of more than 30° on ladders or stairways unless there is reasonable assurance of saving life. In any event, apparatus wearersshould take into consideration the difficulties encountered on steep orcomparatively steep pitches and ladders or stairways, such as insecurefooting, falls, and other obstructions. They should also be reason-ably certain of their ability to return to fresh air unaided. Themaximum distance apparatus wearers should travel in metal minesis given for clear atmospheres under various conditions, with themodifications to be made when an atmosphere is smoky or whenhigh temperature and humidity are encountered:
When the atmosphere is clear but gassy and the dip is lessthan 10°, the maximum distance to be traveled by apparatus wearerson unobstructed traveling should be 1,000 feet on advance and anequal distance in retreat. Where falls or other obstructions intervene,the distance allowable may be restricted to a few hundred feet eachway or even less, depending on the dangers due to the falls or ob-structions. Where water is much over 1 foot deep it is dangerous togo, even along a level road, much farther than 100 feet.
Where the dip is more than 10° and less than about 25° andtravel must be undertaken on the floor rather than on ladders orstairways, apparatus trips of over 500 feet each way are dangerouseven m clear, cool atmospheres, especially if the floor is smooth.
80 PROCEDURE IN SEALING ANI) UNSEALING MINE FIRES
Where obstructions are present, distances even shorter than 500 feetare dangerous. When the dip is over 25°, no apparatus trips shouldbe attempted except on ladders or stairs.
(e) On inclined ladders (dip up to 60°), in good condition andwith no obstructions (such as close platforms, sollars, walls, timbers,or falls), distances up to 200 feet are permissible in clear air, thoughsafe removal from 200 feet of ladderway is difficult if an apparatusw'earer becomes helpless. Where obstructions such as close platforms,timbers, or rock falls intervene in ladderways up to 60°, even shorterexploration with apparatus should not be attenipted.
On ladders sloping 60° to 90°, explorations with apparatusshould not be attempted except in emergency, even though the cir-cumstances as to clearness of atmosphere, obstructions, condition ofladders, etc., are favorable. In explorations under such emergencya rope should always be at hand for handling any member of thecrew who may become ill or otherwise disabled. Under no circum-stances should apparatus wearers climb over 200 feet of ladder at60° to 90°; in general, 100 feet should -be considered the maximum.
In dense smoke, apparatus wearers should travel not morethan a few hundred feet, even if no obstructions intervene; and toprotect each apparatus wearer from falling into holes, he should havea cane or staff with which to feel his way. Similarly, travel indense smoke on a dip of over 10°, whether on the floor or on a ladderor stairway, obstructed or unobstructed, should be restricted to shortdistances, preferably under 100 feet. The life line should always beused during exploration in smoky atmosphere. Goggles may beused to advantage in both clear and slightly smoky atmospheres;several methods are available to prevent fogging, the simplest beingto hold within the goggle a little water to be run over the interiorof the glass when it fogs.
Temperature above 85° F. and humidity above 90 percent willlimit further the allowable distances to be traveled by apparatuswearers, the higher the temperature and humidity the shorter thedistance, with still greater limitation if the surrounding air or gasesare motionless.
o